OCZTVEND2 vs. TRUE vs. HDT-S1283

This article serves only one purpose: test three of the industry's most coveted coolers. Not very long ago Benchmark Reviews published the article Best CPU Cooler Performance - Q1 2008. At the time, the effort we gave in producing our test results seemed well worth the trouble. However, months later we see that there's a lot more to a cooler than just measuring performance with the same common fan. So after even more testing, we now have a full understanding of each CPU coolers individual characteristics and deliver the results to you. Benchmark Reviews is proud to present a three-way fight to the finish: The OCZ Vendetta 2 vs. Thermalright's Ultra-120 eXtreme vs. Xigmatek's HDT-S1283.

Computer hardware is an ever-evolving industry, and since Moore's law only applies to an exponentially growing transistor count then there should probably be another law for cooling. In the very recent past there have been two major trends which have accelerated the performance potential of CPU cooler. That first development was the use of heat-pipes to directly contact with the CPU surface; which resulted in the Heat-pipe Direct Touch technology. The second development is by no mean a new concept, just new to our industry in specific. For many years now heatsinks have been full of right angles, but very recently companies have begun to recognize the need to disrupt smooth airflow and reduce the laminar skin effect which allows air to travel just above the solid surface. Some manufacturers have used at least one of these new concepts in their product design, and only a few are beginning to incorporate both. Benchmark Reviews will see how much this effects the overall performance as we test a large segment of products.

Our scope is limited to stand-alone products only, meaning those products which can be installed and operated without additional critical components needed or kit construction. This generally excludes nearly all liquid cooling systems, which may offer better performance than the products we test. Suffice it to say however, the vast majority of gamers and enthusiasts are using air-cooled solutions and therefore we target this article towards them.

Manufacturers are not expected to enjoy this sort of comparison, since we level the playing field by replacing their included fan (when applicable) with a common unit which we then use for each CPU cooler we test. Manufacturers regularly include fans with their CPU cooler products, and more often than not these fans are very high RPM units which offer great airflow at the expense of an obnoxiously loud noise level. By using the same model of cooling fan throughout each test segment, we can assure our results are comparable across the board. This is one of the more significant changes we have made to our test methodology, since many of the benchmark tests we have conducted in the past have compared the total package. Ultimately we're more interested in the discovering the best CPU cooler performance, and we believe that you'll feel the same way.

We encourage hardware enthusiasts to utilize the equipment available to them, and select the cooling fan that best suits their needs. Just keep in mind that exceptional cooling performance must begin with the CPU cooler, and end with the cooling fan. It's the foundation of the unit that makes a difference, which is exactly what we're after in this article.

In our next section, we offer the thermal conductance values of the entire table of elements. I don't expect many of you to care for this kind of technical information, but for those of you who might not skip over it you'll gain an insight to what the industry uses and what really works.

Conductive Element Reference

Manufacturers have made a small fortune off of confusion tactics and misinformation. Marketing departments often times neglect to refer back to solid science when making their bold claims, which is why we have assembled a complete list of thermally conductive elements in the reference chart below.

It's very well known that Silver, Copper, Gold, and Aluminum together comprise top four most thermally conductive elements. However, without knowing the thermal conductance of these elements you might think the performance was close. As it turns out, Silver and Copper both offer nearly twice the performance of Aluminum when transferring thermal energy such as heat. Aluminum is the least expensive top-tier metal, which explains the popularity. Most Thermal Interface Material and CPU coolers use several different elemental ingredients to work together, but after a careful inspection of the performance levels it comes as a surprise to me that some of the most popular products make use of such poor conductors.

Recipes usually call for only the finest ingredients, and the very same principal is true for overclocker and hardware enthusiast products. Thermal pastes are often times mixed from at least a dozen different components, while heatsink coolers may use only one or two different metals. Armed with the knowledge above, you might expect any silver-based product to be a clear-cut winner... but building a superior product by design is different than what you receive in execution.

Keep these materials in mind as we take a look at the new products Benchmark Reviews has collected for this round-up article, beginning with our first contender...

Xigmatek HDT-S1283

Utilizing the highest order of technology is their cooling fan: pulse width modulation, Xigmatek has combined the efficient design of three exposed copper heatpipes with an extremely durable (and quiet) 120mm fan in their newly released HDT-S1283. Pulse Width Modulation is usually regarded as too complicated for PC fan speed controls, especially when compared against rheostats or linear voltage regulators. Xigmatek cuts no corners in producing a top of the line CPU cooler worth it's weight in gold... or perhaps copper based on the costs of material these days.

When I first received the HDT-S1283 Exposed Copper Heatpipe 120mm CPU Cooler, I silently thanked Xigmatek for designing an after-market cooler which doesn't require me to disassemble my computer and remove the motherboard just to install a CPU back plate. With Anti-vibration rubber, spoiler design, and push-pin & clip systems for both Intel and AMD application, the HDT-S1283 offers an easy to install cooling solution.

From the side view above, you get a very good look at three of the largest copper heatpipes I can recall seeing on a CPU cooler. Xigmatek uses 100% copper in their 8mm heatpipes, which dramatically improves the evaporation and condensation cycle in the HDT-S1283.

A single 120mm cooling fan is included with the Xigmatek HDT-S1283, which is more than enough to move a large amount of air over the fins and heatpipes. After you see the results (keep reading, don't skip to the results page), you will understand why I am not going into detail about attaching a second 120mm fan to the backside of the heatsink.

The backside of the unit (shown in the image below) has a curved "valley" indention, which really serves no true purpose in this design. I think that if I were to ever design a "fin-sink" plate, it would utilize as much footprint space as possible; adding curves might look nice, but they take away from the cooling surface.

For Intel motherboard users, the Xigmatek HDT-S1283 Exposed Copper Heatpipe 120mm CPU Cooler must first be installed without the fan attached, and once the pins are depressed into the motherboard you can mount the fan. Once each of the four depression clips secures the heatsink to the motherboard, the soft rubber T-hooks press into the aluminum fin channel as shown in the image above. Installation was among the easiest I have ever experienced, which amounted to only one extra step more than the OEM cooler supplied by Intel.

The most critical part of any heatpipe cooler is the arrangement of the actual heatpipe rods. In any heatpipe design, the liquid inside the rod is heated to a very low boiling point. This low boiling point evaporates the liquid into a gas, which carries the heat to the ends of the heatpipe. Once it reached the cooler end(s) of the heatpipe, the chilled gas condenses into a liquid, which will then travel back down to the base for a cooling effect.

The real benefit I see to the design of the HDT-S1283 is two-fold:

1. The liquid will reach the low boiling point faster thanks to the shaved copper face of the pipe.
2. Evaporated gas will have two different ends to carry exchange the heat, effectively cooling twice as fast as a single ended rod.

A closer look at the mating surface on the Xigmatek HDT-S1283 shows the three exposed copper 8mm heatpipes resting in an aluminum base. The Intel depression-clip rails attach by a single machine screw at each end, as you can see by the threaded screw holes in the base shown below.

When applying thermal interface material to the Xigmatek HDT-S1283 exposed copper heatpipe 120mm CPU cooler, it's very important to understand that most white zinc-oxide (white) thermal paste will cause oxidation to the copper heatpipes upon contact and possible decrease the effectiveness of the material. Benchmark Reviews offers a complete guide on the Best Thermal Paste Application Methods, which includes instructions for HDT coolers.

At the moment, Xigmatek's HDT-S1283 CPU cooler is just turning one year old. There are a multitude of products that are either similar or identical, which is fair considering that Xigmatek doesn't own the patent for HDT anyway. Presently the HDT-S1283 is available from NewEgg for $36.99. Alternatively, NewEgg also offers the RVT-12025 for $31.99, which is considerably less expensive and is an exact clone (but comes with a much lower-volume fan for reduced noise levels).

OCZ Vendetta 2

OCZ Completely surprised us when the original Vendetta HDT CPU cooler was tested and secured a top position among our collection of coolers. It was later discovered that the loud high-volume 92mm fan was included for a reason: the fins were much longer than the Xigmatek HDT-S963 it was loosely based off of and needed the extra push to force air past them. But OCZ didn't leave well enough alone, and recognized where there could be the potential for even more performance out of the HDT design. So back to the design table they went, and created the OCZ Vendetta 2 HPT CPU Cooler OCZTVEND2.

The OCZ Vendetta 2 is an efficient new CPU cooler that utilizes a distinctive stacked fin design and heat-pipe Direct Touch (HDT) technology. In this version of their popular cooler, OCZ designed the OCZTVEND2 to use large 8-gauge copper heat-pipe rods combined with a large low-noise fan. Together these items match to offer a perfect balance, allowing the Vendetta 2 to quietly cool even the most robust quad-core system.

Utilizing the proven performance of their original Vendetta HTD design, the Vendetta 2 has direct contact with the processor using three copper heat pipes to ensure the most rapid heat transfer and a lighter weight. OCZ's unique dimple micro-configuration of the stacked aluminum fins adds turbulence, reducing the skin effect of laminar air flow for more efficient circulation within your case.

The Vendetta 2 also offers an extra performance boost over the more compact original version. The ultra-quiet 120mm fan comes equipped with anti-vibration rubber latches to reduce excess noise, so high-volume airflow doesn't have to mean high-volume noise like the 92mm version fan.

OCZTVEND2 Specifications

• For Sockets AMD 754/755/939/AM2 and Intel LGA775
• 3 Pure Copper heat pipes for superior heat dissipation
• Pure Aluminum fins for ultimate durability
• Heatsink Dimensions:(W)120 x (H)50 x (D)159mm
• Fan Dimensions: (L)120 x (W) 120 x (H)25mm
• Rated Voltage: 12V DC
• Fan Speed: 800-1500 RPM
• Fan Air Flow: 65-81 CFM
• Noise Level: 20-32 dBA
• Bearing type: Rifle
• Connector: 4 pin with PWM
• Includes: 120mm Fan with rubber connectors
• Mounting Hardware for all above CPUs

As with all HDT coolers, there are small "gutters" to each side of the heat-pipe rod. These gutters are very small, but they are still large enough to collect excess Thermal Interface Material. It's recommended that a carbon and aluminum-oxide based TIM be used with all copper surfaces. There are many excellent options tested in our 33-Way Thermal Interface Material Comparison article.

The OCZ Vendetta 2 was very easy to install since it uses the standard pin-style compression clips. I have noticed that both the original Vendetta and the new Vendetta 2 both have a clip system that requires more force to secure than an OEM Intel cooler. This gives the Vendetta 2 a much stronger mount to the CPU in return. Although the Vendetta 2 design is very similar to the Xigmatek HDT-S1283 cooler, there are several key differences separating the two products. Presently NewEgg is listing the OCZTVEND2 for $49.99.

Thermalright Ultra-120 eXtreme

Thermalright introduced the Ultra-120 eXtreme many months back, but it wasn't until recently that I discovered that some enthusiasts considered it better than the leading HDT solutions. In all honesty, I had never tested this cooler before now because Thermalright would claim that there were enough reviews out on the product already whenever I would request it. But now that I've discovered some overclockers giving it high praise, I had to know how well it compared.

Thermalright is secretly one of my favorite manufacturers from way back in the day. The first heat-pipe cooler I ever used was the Thermalright SI-128, and two years back it was performing so much better than the competition that everyone began using their design. Just like the saying goes: "the more things change the more they stay the same".

One of the things that I remember most about this industry is the few names that forge ahead with producing high-quality products without much marketing hype. Similar to the way Crucial packages it's system memory modules, Thermalright packages their coolers inside a plain brown box. This approach used to make me wonder if they were simply trying to save money or avoid passing on the cost of marketing to the consumer. But since neither of these companies has yet to put out a "bad" product, I think the plain brown packaging is more of a message: we don't need to dress up our products... they perform well without the hype.

Among the short list of other unchanged habits in the Thermalright factory is the absence of a factory-included cooling fan with their products. This allows the consumer to match their CPU cooler to the best fan that fits their needs, and in all actuality is probably the best option for enthusiasts (but may also be confusing for inexperienced consumers).

Of the new product changes, Thermalright has adapted a proprietary bent winglet design to minimize airflow resistance in the Ultra-120 eXtreme. I am a little skeptical of their stated intention, since streamlining will reduce resistance and bends will do exactly the opposite. But aside from the wording, this is similar in concept to OCZ's dimple micro-configuration which adds turbulence and reduces the skin effect of laminar air flow as a result.

Both sides of the Ultra-120 eXtrme are made to accommodate a 120mm cooling fan, and Thermalright has included the necessary wire retaining brackets to enable this configuration. Unlike many other manufacturers that use a "U" design with four heat-pipe rods, Thermalright makes use of six total nickel-plated copper heat-pipe rods amounting to twelve cooling ends in the circuit.

When I stop to think about it, there really aren't very many other coolers that can boast this many heat-pipes in one small unit. Even the overgrown Scythe Mugen SCINF-1000 only offered five heat-pipe rods (with ten cooler ends total), and that cooler is easily three times as large as the Ultra-120 eXtreme.

Exactly opposite of Noctua's mirror finish, the Ultra-120 eXtreme features a very uneven "freshly ground" finish. The image below is a close-up of the eXtreme's CPU mating surface, which is convex by design and meant to compensate for the irregular finish of processor Integrated Heat Spreaders. Nevertheless, the contact surface is full of crevices and not likely to offer exceptional thermal conductivity because of the additional thermal paste which will be necessary. I'm biting my tongue for now and not going into detail, but you'll want to read through the Surface Finish Impact portion in the testing methodology section which follows.

Our test sample of the Ultra-120 eXtreme came with the latest retaining clip system design, and did not require any additional washers to increase compression onto the processor. We understand that older versions were plagued with a weak mounting strength, but I assure you that this version had more than enough tension to make it difficult to completely tighten down.

Although the Thermalright Ultra-120 eXtreme CPU cooler has been on the market for almost two years, prices for the ULTRA120EXTREME are still hovering around $60. Please keep in mind that the TRUE does not include a fan, and one (or two, if desired) must be purchased separately.

Thermal Interface Material Application

Over the past several months, I have read an unreasonable number of discussion forum posts which offer inaccurate and often times incorrect information. It's not really all that surprising to read poorly conceived information on the Internet, which seems to be a anonymous means of passing off opinion for fact. As a general rule we don't let too many things go untested, and the advice of wanna-be experts is not doing the hardware enthusiast and overclocker community any good. In this article, Benchmark Reviews dispels myth and establishes fact on the topic of proper application in our Best Thermal Paste Application Methods article.

After we wrote our 33-Way Thermal Interface Material Comparison article, many enthusiasts argued that by spreading out the TIM with a latex glove (or finger cover) was not the best way to distribute the interface material. Most answers from both the professional reviewer industry as well as enthusiast community claim that you should use a single drop "about the size of a pea". Well, we tried that advice, and it turns out that maybe the community isn't as keen as they thought. The example image below is of a few frozen peas beside a small BB size drop of OCZ Freeze TIM. The image beside it is of the same cooler two hours later after we completed testing. If there was ever any real advice that applies to every situation, it would be that thermal paste isn't meant to separate the two surfaces but rather fill the microscopic pits where metal on metal contact isn't possible.

After discussing this topic with real industry experts who are much more informed of the process, they offered some specific advice that didn't appear to be a "one size fits all" answer:

1. CPU Cooling products which operate below the ambient room temperature (some Peltier and Thermo-electric coolers for example) should not use silicon-based materials because condensation may occur and accelerate compound separation.
2. All "white" style TIM's exhibit compound breakdown over time due to their thin viscosity and ceramic base (usually beryllium oxide, aluminum nitride and oxide, zinc oxide, and silicon dioxide). These interface materials should not be used from older "stale" stock without first mixing the material very well.
3. Thicker carbon and metal-based TIM's may benefit from several thermal cycles to establish a "cure" period which allows expanding and contracting surfaces to smooth out any inconsistencies and further level the material.

The more we researched this subject, the more we discovered that because there are so many different cooling solutions on the market it becomes impossible to give generalized advice to specific situations. Despite this, there is one single principal that holds true in every condition: Under perfect conditions the contact surfaces between the processor and cooler would be perfectly flat and not contain any microscopic pits, which would allow direct contact without the need for Thermal Interface Material. But since we don't have perfectly flat surfaces, Thermal Material must fill the tiny imperfections. This is where our testing comes into play.

Surface Finish Impact

Here's the part I've been waiting to reveal... the importance of surface finish in relation to the impact on thermal conductivity. CPU coolers primarily depend on two heat transfer methods: conduction and radiation (heat-pipes also add convection). This being the case, let's start with conduction as it related to the mating surface between a heat source and a cooler.

Because of their density, metals are the best conductors of thermal energy. As density decreases so does conduction, which relegates fluids to be naturally less conductive. So ideally the less fluid between metals, the better heat will transfer between them. Ultimately, this means that the perfectly flat and well-polished surface (Noctua NH-U12P) is going to be preferred over the rougher and less even surface which required more TIM to fill the gaps (Thermalright Ultra-120 eXtreme).

Heat radiation is different however, and requires exactly the opposite. Because gases (air) are naturally poor heat conductors, surface area is key to the performance of cooling through radiation. This type of cooling is what you commonly see automobile radiators, which utilize large arrays of metal fins to radiate heat to be drawn away by a fan. The same is true for the CPU cooler, which needs as much surface area as possible to optimize it's radiative effects. OCZ and others have recognized that the surface of a heatsink does not have to be the sum of its overall size. By adding dimples and bends, the surface area is increased without growing the overall size.

To sum it all up, science teaches us that a smooth flat mating surface is ideal for CPU coolers so that less Thermal Interface Material is used. Because these coolers are using fans to force air over the heatsinks fins, the overall surface area of those fins should be as large and uneven as possible. In the next section we'll find out just how well all of these principals worked for our collection of test products.

Testing Methodology

Testing was conducted in a loosely scientific manner. Ambient room temperatures levels were held to within one degree of fluctuation measured at static point beside the test equipment with a calibrated digital thermometer. All coolers had their original manufacturer-supplied fan removed and replaced with our common test fan listed in the support equipment section below. Each product then received the same amount of Thermal Interface Material (specified below), which amounted to roughly a BB-sized drop placed onto the center of the CPU. The CPU cooler product being tested was then laid down flat onto the CPU, and compressed to the motherboard using the supplied retaining mechanism. If the mounting mechanism used only two point of force, they were tightened in alternation; standard clip-style mounting with four securing points were compressed using the cross-over method. Once installed, the system was tested for a baseline reading prior to testing.

At the start of each test, the ambient room temperature was measured to track any fluctuation throughout the testing period. EVEREST Ultimate Engineer Version 4.20.1170 was then utilized to create core loads and measure each individual CPU core temperature. It's important to note that software-based temperature readings reflect the thermistor output as recorded by the BIOS. For this reason, it is critically important to use the exact same software and BIOS versions throughout the entire test cycle, or the results will be incomparable. All of the units compared in our results were tested on the same motherboard using the same BIOS and software, with only the product itself changing in each test. These readings are neither absolute nor calibrated, since every BIOS is programmed differently. Nevertheless, all results are still comparable and relative to each products in our test bed.

One unfortunate problem is that CPU's report temperatures as a whole number and not in fractions. This in turn causes the motherboard BIOS and subsequent software applications such as EVEREST to also report to the nearest whole number. To compensate for this, our tests were conducted several times after complete power down thermal cycles. Conversely, the ambient room temperature levels were all recorded and accurate to one-tenth of a degree Celsius.

Test System

Motherboard: Gigabyte GA-X48T-DQ6 (Intel X48 Chipset) with version F4 BIOS
Processor: Intel E8200 Core 2 Duo 2.66GHz (Overclocked to 3.6 GHz)
System Memory: Corsair PC3-14400 DDR3 1800MHz
Audio: HT Omega Claro Plus+ AD8620BR Op Amp Sound Card
Disk Drive 1: OCZ SATA-II 32GB 2.5-Inch SSD OCZSSD2-1S32G
Disk Drive 2: (Paging File) MemoRight GT MR25.2-064S 2.5-Inch 64GB SATA SSD
Optical Drive: ASUS BC-1205PT SATA Blu-ray Disc Optical Drive
Enclosure: Lian Li PC-B25B Black Aluminum Mid-Tower ATX Case
PSU: ePower Technology EP-1200P10 xScale 1200W PSU
Grpahics: ZOTAC GeForce 9800 GTX 512MB Video Card
Monitor: Honeywell 22-Inch LCD Monitor MT-SY-HWLM2216
Operating System: Windows XP Professional SP-3 (optimized to 16 processes at idle)

Support Equipment

• OCZ Freeze Thermal Interface Material (No curing time necessary or given)
• Noctua 120mm cooling fan, model NF-P12 (54 CFM @ 20 dbA)
• Yate Loon 120mm cooling fan, model D12SH-12 (88 CFM @ 40 dbA)

All of our tests are conducted using two different product orientations: horizontal and vertical. So far as we can tell, Benchmark Reviews is probably the first website to test with this method. We do this because there are different requirements for each persons system, and it's a good idea to know what effect gravity has on the product.

At the start of our test period, the test system is orientated sideways in a flat "HTPC" position which places the motherboard and processor horizontally to face up towards the ceiling. Next, the computer system is powered on and EVEREST system stability tests are started with Stress CPU and Stress FPU options selected. Then for a minimum of ten minutes EVEREST loads each CPU core to 100% usage, which drives the temperature to its highest point. Finally, once temperatures have sustained a plateau, the ending ambient room temperature and CPU core levels are recorded and the first benchmark segment is complete. EVEREST remains running at full load into the next test segment.

The second benchmark segment begins by simply turning the test system vertically upright into a standing tower position, so that the motherboard and CPU are facing to the side. Many of the products we have tested utilize a "U" pattern in the heat-pipe rods, and the upright system orientation favors this particular product design because it removes the effect of gravity on the heat-pipes' thermal cycle. For a minimum of five additional minutes EVEREST continues to load each CPU core, and once temperatures have plateaued the ending ambient room temperature and CPU core levels are recorded. This process was identical for all cooling solutions used in our benchmark tests segments.

Test Results: Low-Output Fan

When it comes to personal computers, you could probably divide users into two groups for almost any topic. In regards to fan noise, there are those of us who want it quiet while other will tolerate an eardrum-ringing whine. Since noise is a problem, and not a solution, I believe that most enthusiasts want as much performance as they can get while sacrificing as little serenity as possible. That's what this test section is all about.

While the name of this section revolves around "low-output", the term is relative to the person using it. Benchmark Reviews feels that Noctua does an excellent job of producing some of the very best low-noise fans which still manage decent airflow. In our low-output tests we have used the Noctua NF-P12 120mm cooling fan for all coolers, which creates 54 CFM at a lightly-audible 20 dbA.

Benchmark Reviews is still a rather new website, even though we have just proudly completed our first year on the web. So in the spirit of improving on the old ways of testing, we have decided it was time for the industry to see things from a new perspective:

1. We will test coolers using a common fan configurations, so that air speed and volume remain constant between products and thereby isolate cooler performance.
2. We will test coolers in both a horizontal and vertical position, since heat-pipes are effected by product orientation and gravity.

Like we mentioned at the beginning of this article, the CPU cooler must perform for itself before a fan can improve upon it. The concept behind this is that coolers are isolated and more fairly compared. Now obviously this will have an impact on our results, which will not match the results of other websites using the factory included fan for their tests.

When I tested each cooler, I made certain to keep the hardware settings identical across the test platform. This would enable me to clearly compare the performance of each product under identical conditions. While the ambient room temperature did fluctuate between 20~21°C, this would not be enough to cause a noticeable impact on our test results (since thermal difference scores were used).

Our testing begins with a horizontally positioned system, similar to a HTPC or rack mount server unit. Some may think that a difference doesn't exist between the horizontal and vertical orientations and that the cooler will perform the same no matter what, but we were a little surprised by the new benchmark results. With a moderately low-output fan attached to each cooler, there were seven test samples taken within our ambient temperature range. In the charts below each cooler displays a thermal difference, which is the difference between the ambient room temperature and the recorded temperature of the processor cores.

For HTPC builders using full-height enclosures, you want to consider the OCZ Vendetta 2 (OCZVEND2). which narrowly seated itself atop the competition for our low-output fan horizontal position tests. The Thermalright Ultra-120 eXtreme comes in at nearly the same performance, followed by the Xigmatek HDT-S1283.

Now obviously these results are extremely close, which means that ultimately they will all perform roughly the same in most environments. That being said, it comes down to price, and perhaps application compatibility. The Kingwin RVT-12025 is a poor-mans HDT-S1283 since it costs $31.99 compared to $36.99, and they are identical in unit construction (but Kingwin includes a lower-volume silent fan).

During our testing for the Best CPU Cooler Performance - Q1 2008 article, nearly every cooler that used a "U" shaped heat pipe rod in their design did better in the vertical (standard upright tower) position. There seemed to be one dissident though, because the Thermalright Ultra-120 eXtreme acted exactly opposite and performed better in every horizontal test we conducted.

For every other cooler, having the unit positioned with the rods running horizontally proved to offer a cooling benefit. This was especially true for the Xigmatek HDT-S1283 and OCZ Vendetta 2, which had the most significant drop in temperature out of the bunch. This goes to show you that heat-pipes are in fact prone to suffer the effects of gravity in their design. Once the vapor cools and becomes liquid, it seems to have an easier time completing the thermal circuit from side to side than it does from top to bottom. So let's see how these coolers performed with the stress of gravity removed from them:

The vertical test results are going to be the most relevant to enthusiasts and overclockers, since upright tower computer cases are almost always used to build their systems, In the second half of our low-out fan benchmark testing, the OCZ Vendetta 2 proved itself worthy of the Golden Tachometer Award it received a few months back. If you're not interested in wearing hearing protection around your computer, then the OCZ Vendetta 2 is a sure winner for the sub-$50. Not far behind was the trusty Xigmatek HDT-S1283, which could also find itself a nice home for anyone tight on cash but long on overclocking ambition. The Thermalright Ultra-120 eXtreme did not like the vertical (upright tower) position, and liked the low-output Noctua fan even less, yet still did considerably well for such a tightly packed finsink array.

In summary, if you're building a system that places an emphasis on low sound levels, you'll want to pick your cooler carefully. OCZ's Vendetta 2 is an excellent choice for either HTPC or tower builds, with the Xigmatek HDT-S1283 coming in right behind it. For under $50 USD, you can either keep with the stock fans and see similar results, or you can dig a little deeper and force-feed the cool air with a nice Yate Loon fan (like we used for our next section). The Thermalright Ultra-120 eXtreme performed very well, and kept in-step with the best of the best, but at $60 or more for the cooler alone, you will spend at least another $10-$20 on a fan. Even still, that fan is probably not going to be a low-output fan like we used here, because the dense fin array practically demands higher-output solutions.

Test Results: High-Output Fan

In our last section, the OCZ Vendetta 2 proved itself worthy of low-volume low-noise fan applications where comfort is more desirable than a maximum overclock. But we're moving on, because almost anyone who buys an aftermarket cooler is doing so because of the free performance waiting to be unlocked through hardware tweaking. Overclockers are already willing to take their hardware to the breaking point, so it stands to reason that reduced fan noise is not a top priority.

This section is labeled high-output, which shouldn't be mistaken for highest-output. I am aware that there are much more impressive fans available, such as the 120 CFM screamers that require a bolt-on kit to retain them. But in my experience, the Yate Loon D12SH-12 is one of the best 120mm cooling fans available in regards to the noise to performance ratio. The D12SH-12 cooling fan forces an impressive 88 CFM of air at a moderately noisy 40 dbA. Personally, I can't suffer anything that produces higher sound levels than this, since gaming requires headphones and casual computing is almost impossible.

The high-output testing begins at the horizontally position, similar to a HTPC or rack mount server unit. With the high-output Yate Loon D12SH-12 fan attached to each cooler, there were ten seven test samples taken within our ambient temperature range. In the charts below each cooler displays a thermal difference, which is the difference between the ambient room temperature and the recorded temperature of the processor cores.

In our low-output tests, the OCZ Vendetta 2 was our top-contender by a narrow margin over the TRUE, but with a much more powerful fan pushing air past the dense array of fins the wind has changed direction. The Thermalright Ultra-120 eXtreme posts an impressive lead over the top competition, and clearly performs the best in our high-output horizontal position testing. I can't realistically see anyone in their right mind using the high-output fan inside an HTPC, but desktop workstations and rack mount server units could certainly benefit here.

The Vendetta 2 wasn't very far behind, which could make a good argument for anyone not wanting to spend very much on an aftermarket cooler. However the Xigmatek HDT-S1283 trailed behind by just over a full degree of thermal difference, which is good and fine considering that these three products are considered by many to be the best of the best, but now that the HDT-S1283 has so much competition (along with a less-expensive Kingwin RVT-12025 clone) it doesn't make good sense anymore.

When I tested each cooler, I made certain to keep the hardware settings identical across the test platform. This would enable me to clearly compare the performance of each product under identical conditions. While the ambient room temperature did fluctuate between 20~21°C, this would not be enough to cause a noticeable impact on our test results.

Now for the test that matter most to overclockers: the high-output vertical position benchmarks. Nearly every single overclocker uses a tower computer chassis, which stands upright. Additionally, it's probably a safe bet that most overclockers don't particularly mind the noise that these high-output fans create. So for this test segment, I tested each cooler for a total of fifteen test samples, and averaged the thermal difference results below.

When the testing was complete and the results were calculated, it surprised me to find these coolers performing so close to one another. In most cases, I would normally dismiss some portion of my results as margin of error, but each of the tests were very much identical to the entire collection for each product. For a short while I had suspected that the Thermaltake Ultra-120 eXtreme would beat the entire bunch, but then I remembered how the TRUE actually did better in the horizontal position than it does in vertical environments. So it didn't really surprise me when the Ultra-120 eXtreme produced the same (exact) thermal difference for both positions, because it actually got worse in the vertical position testing under low-output fan testing.

Once again, OCZ Vendetta 2 produced a very-narrow lead ahead of the Thermalright Ultra-120 eXtreme, making the OCZVEND2 our most highly-recommended cooler. This isn't going to make many people happy, since I have heard nothing but petty complaints from several members of the overclocking community who seem to be personally attached to their small investment. So for them, I'll dedicate a few more words: move on. Technology changes, and the two year old design of Thermaltakes Ultra-120 eXtreme isn't going to get any better with time... in fact, their upcoming TRUE Black edition is exactly identical with anodized black fins. That's not what I consider progress from the manufacturer. But I will avoid a long dialog slamming the design flaws of the TRUE, and instead shed some light on where super-enthusiasts can go from here in the next section.

CPU Cooler Final Thoughts

I really enjoyed producing this article, but probably for the wrong reasons. To begin with, I want to know which product performs the best just as much as you do; maybe even more. But thanks to having so many products available to me for testing at the same time, I have the advantage of finding a winner where nobody is looking and down-grading the product everyone is so hyped about. Several times in the past year I have found myself exchanging dialog with readers who question my results because they have experienced a different result with one particular product. Plainly put: all of my testing and the subsequent benchmark results are gathered in the exact same manner on the same test system during the same benchmark period. So if you personally feel that I didn't manage to somehow test these products to your standards, you will still have to commit to the fact that they were all tested identical fashion - apples to apples.

No doubt there will be a few readers who will scoff at my results, and claim that anyone with ten minutes of experience will "lap" the processor's integrated heat spreader smooth as well as polish the CPU coolers mating surface. Sure, I concede that the bonafide overclocker with more time on his/her hands than the average hardware enthusiast will wet-sand their equipment so that they can get a few extra degrees of cooling performance. But for the other 99.99% of the consumer population, this is what you can expect from these cooling products if you want the CPU cooler to perform right out of the box.

There are numerous ways to improve upon the performance that any one of these products has offered. Take for example the Thermalright Ultra-120 eXtreme: most enthusiast like to modify this product by lapping the surface and adding additional mounting pressure by using a washer. I for one believe this to be more of a necessity than anything else, since Thermalright designed the surface with an intentionally uneven convex finish. To a lesser extent, you could also file and polish the mating surface of any one of the Heat-pipe Direct Touch coolers and then use bolt-on backplate mounting kit (such as the Xigmatek Cross-bow system).

Conclusion: Best of the Best

In our Best CPU Cooler Performance - Q1 2008 article, one product stood out among the crowd and outperformed every other test product: the OCZ Vendetta 2 Heat-pipe Direct Touch 120mm CPU cooler. Three months later, the OCZVEND2 is back on top again. It has it's limits, but for the vast majority of overclockers and enthusiasts it will offer more than enough performance under both low- and high-volume fan configurations.

The OCZ Vendetta 2 was very easy to install since it uses the standard pin-style compression clips. I have noticed that both the original Vendetta and the new Vendetta 2 both have a clip system that requires more force to secure than an OEM Intel cooler. This gives the Vendetta 2 a much stronger mount to the CPU in return. Although the Vendetta 2 design is very similar to the Xigmatek HDT-S1283 cooler, there are several key differences separating the two products. Presently NewEgg is listing the OCZTVEND2 for $49.99.

For anyone wanting top-level cooling performance at recession-level pricing, the Xigmatek HDT-S1283 and its clone RVT-12025 are perfect solutions. At the moment, Xigmatek's HDT-S1283 CPU cooler is just turning one year old. There are a multitude of products that are either similar or identical, which is fair considering that Xigmatek doesn't own the patent for HDT anyway. Presently the HDT-S1283 is available from NewEgg for $36.99. Alternatively, NewEgg also offers the RVT-12025 for $31.99, which is considerably less expensive and is an exact clone (but comes with a much lower-volume fan for reduced noise levels).

The end-goal is different, but it always remains the same: overclockers want more. The question is how much more? If you're after the absolutely highest possible overclocks and need the most out your cooling solution, then the Thermaltake Ultra-120 eXtreme actually has an advantage. Sure, it's more expensive, and it will require tedeous lapping of the surface to make it flat, but there are still a few things that it can do that other cannot: such as mount a second fan. For that small bunch of ultra-enthusiasts, a $100+ air-cooled solution doesn't seem absurd if it delivers a few extra degree of cooling performance.

Although the Thermalright Ultra-120 eXtreme CPU cooler has been on the market for almost two years, prices for the ULTRA120EXTREME are still hovering around $60. Please keep in mind that the TRUE does not include a fan, and one (or two, if desired) must be purchased separately.

Ultimately though, this article has to reach a large and diverse crowd of enthusiasts. My advice is this: identify your needs and estimate your budget, because I have covered the three best coolers for every configuration in this article. If your an overclocker who like to keep the peace, the Vendetta 2 offers great low-volume performance. If cost is an issue, the Xigmatek HDT-S1283 and its Kingwin RVT012025 clone are perfect. Finally, if time and money are readily available and noise isn't nearly as important as top-end cooling, the Thermalright Ultra-120 eXtreme is your best choice.

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