Seagate Momentus XT 750GB Hybrid Drive Review

Manufacturer: Seagate Technology LLC
Product Name: Momentus XT Solid State Hybrid Drive
Model Number: ST750LX003
Price As Tested: $245 MSRP

Full Disclosure: The product sample used in this article has been provided by Seagate

Mechanical hard disk technology has been the traditional standard for decades, refined to the point where it can deliver massive storage capacity beyond 3TB. Recently introduced solid-state drive storage solutions have begun pecking away at the market share thanks to their tremendous speeds and operational performance. Each offers an advantage over the other, leading manufacturers to seek out a hybrid solution that delivers quick access and large data capacity. The original 500GB Seagate's Momentus XT hybrid had the right ingredients, just not enough polish. More than a year later, the Seagate Momentus XT 750GB solid state hybrid drive (SSHD) returns with a double-size 8GB SLC NAND flash SSD buffer fused onto a larger 7200-RPM hard drive. Seagate FAST Factor firmware and Adaptive Memory Technology negate the need for third-party software, and makes this an all-in-one hybrid SSD solution. In this article Benchmark Reviews tests the Seagate Momentus XT (750GB model ST750LX003) in single and RAID-0 configurations against its predecessor, and several of the fastest notebook storage devices available.

The Hard Disk Drive (HDD) technology has enjoyed a long service life in the computer industry, and only recently have Solid State Drive (SSD) storage solutions threatened to replace it. While the HDD offers higher capacity at a better price per Gigabyte, SSDs offer tremendous speeds and operational performance. Seagate believes they've achieved the optimal blend of each, presenting their second-generation solid state hybrid drive. Seagate's Momentus XT 750GB Hybrid relies on an Adaptive Memory technology that works by identifying patterns in how often certain digital data is used, which caches qualified user data access transactions onto the 8GB SSD. We experiment with two Seagate Momentus XT Hybrid drives in a striped RAID-0 array to see just how well Adaptive Memory Technology keeps up. Yet, while the name is Solid State Hybrid Drive (SSHD), the product is really a 'smart' HDD with an extremely large memory buffer.

When SSD storage devices first arrived to market, hardware review websites had to gradually understand the new technology and how to benchmark its performance. Testing SSDs required more preparation than HDD benchmarks, and operational performance was vastly more relevant then traditional transfer speeds. For this purpose, our usual collection of benchmark test-metrics won't paint an accurate picture. ATTO and Iometer will offer traditional measurements, but these performance readings will ignore Seagate's Adaptive Memory algorithm that improves the operation of accessing these programs and not the benchmark results. Repetitive processes will benefit from SSD-like performance, but one-time file transfers and initial application access will be handled by the enhanced hard drive. In addition to traditional HDD/SSD benchmark tests, the Seagate Momentus XT Solid State Hybrid will be used for real-world tasks and compared against the competition.

Bandwidth Speed vs Operational Performance

As we've explained in our SSD Benchmark Tests: SATA IDE vs AHCI Mode guide, Solid State Drive performance revolves around two dynamics: bandwidth speed (MB/s) and operational performance (IOPS). These two metrics work together, but one is more important than the other. Consider this analogy: operational IOPS performance determines how much cargo a ship can transport in one voyage, and the bandwidth speed is how fast the ship moves. By understanding this and applying it to SSD storage, there is a clear importance set on each variable depending on the task at hand.

For casual users, especially those with laptop or desktop computers that have been upgraded to use an SSD, the naturally quick response time is enough to automatically improve the user experience. Bandwidth speed is important, but only to the extent that operational performance meets the minimum needs of the system. If an SSD has a very high bandwidth speed but a low operational performance, it will take longer to load applications and boot the computer into Windows than if the SSD offered a higher IOPS performance.

Closer Look: Seagate Momentus XT

The Seagate Momentus XT Solid State Hybrid Drive looks identical to other 2.5" notebook hard drive storage products, so there's not much to report on the appearance. However, it's the inside of this drive that makes it unique. An 8GB Single-Layer Cell (SLC) NAND flash memory resides near two disk platters, and makes up the drives SSD cache. These platters have an operating rotational speed of 7200 RPM on the 750GB Seagate Momentus XT, and paired to 32MB of DRAM buffer memory. Going forward, Seagate has retired the 250GB and 320 capacities for Momentus XT, but continues to offer the 500GB first-generation version along with the new 750GB second-generation product:

• 500GB Momentus XT - ST95005620AS (first generation)
• 750GB Momentus XT - ST750LX003 (second generation)

Seagate's Momentus XT is best suited for notebook computer installations that fit a 2.5" drive, but this Solid State Hybrid Drive can easily be installed into most desktop systems without the need for any adapter. Seagate Momentus-XT hybrid drives have been designed with a focus on enhancing real-world user experience while maintaining a large storage capacity. Using their refined Seagate Adaptive Memory Technology, the Seagate Momentus XT learns which programs need to be cached onto the SSD all based on actual usage patterns.

While marketed as a Solid State Hybrid Drive, the Seagate Momentus XT is actually a hard drive first and foremost. This means that if the 8GB SSD cache ever fails, which is unlikely given that its uses single-layer cell (SLC) NAND flash components, the Momentus XT continues to operate as a hard disk drive without any lost data. This could prove critical for those users in need of a less volatile storage solution.

While Momentus XT is more like a hard drive than a SSD, it's still very different than your average hard drive. For example, the WD VelociRaptor features and operating shock (read) value of 65G measured at 2-ms, and non-operating shock of 300G. Conversely, all Momentus XT SSHDs are safe up to 350G's operating shock and 1000G's non-operating.

In the next few sections we test how well the new 2nd-generation 750GB Seagate Momentus XT compares to the 1st-generation 500GB model, as well as other hybrid and solid-state storage solutions. Join us...

SSD Hybrid Features

At the core, Momentus XT is a high-performance 7200RPM drive with 32MB of drive level caching and a SATA 6Gb/s interface. Integrated into the electronics of the drive is 8GB of Single Level Cell (SLC) high- speed NAND flash. Momentus XT features a new technology - Seagate FAST Factor - to synergize the communication and data intelligence between the NAND and rotating media. FAST Factor and Adaptive Memory Technology combine to create a user experience of instant response, instant boot and instant gratification.

FAST Factor Technology

According to Seagate, FAST Factor boot gives laptop users the instant response they need to get moving fast. Booting nearly as fast as an SSD, the Momentus XT drive with FAST Factor boots up to 3 times faster than a traditional 5400RPM drive in a laptop PC. Your boot-up time will never slow you down again. Bottom line: You get up and running faster.

FAST Factor flash management provides seamless integration of hardware, firmware and high-speed NAND flash while maintaining data under all configurations-in any system, using any operating system and with any driver. For fast application loads and overall SSD-like speed of response
from your system, FAST Factor flash management keeps you moving. Bottom line: You get up and running faster with the applications you use most.

Seagate Adaptive Memory

Technology Adaptive Memory technology is a self-learning algorithm designed to deliver SSD-like response from your favorite applications and files. Adaptive Memory selectively copies data that is the most frequently read and time-consuming to retrieve into the flash, giving you an instant-response experience.

Momentus XT Specifications

Drive Testing Methodology

Solid State Drives have traveled a long winding course to finally get where they are today. Up to this point in technology, there have been several key differences separating Solid State Drives from magnetic rotational Hard Disk Drives. While the DRAM-based buffer size on desktop HDDs has recently reached 64 MB and is ever-increasing, there is still a hefty delay in the initial response time. This is one key area in which flash-based Solid State Drives continually dominates because they lack moving parts to "get up to speed".

However the benefits inherent to SSDs have traditionally fallen off once the throughput begins, even though data reads or writes are executed at a high constant rate whereas the HDD tapers off in performance. This makes the average transaction speed of a SSD comparable to the data burst rate mentioned in HDD tests, albeit usually lower than the HDD's speed.

Comparing a Solid State Disk to a standard Hard Disk Drive is always relative; even if you're comparing the fastest rotational spindle speeds. One is going to be many times faster in response (SSDs), while the other is usually going to have higher throughput bandwidth (HDDs). Additionally, there are certain factors which can affect the results of a test which we do our best to avoid.

Test System

• Motherboard: ASUS P8P67 EVO (Intel P67 Sandy Bridge Platform, B3 Stepping)
• Processor: Intel Core i7-2600K 3.4 GHz Quad-Core CPU
• System Memory: 16GB Kingston DDR3 1600MHz CL6-6-6-18
  • 4GB RAM-Disk partition from system memory
• SATA 6Gb/s Storage HBA: Integrated Intel P67 Controller
  • AHCI mode - Intel Rapid Storage Technology Driver 10.1.0.1008
• SATA 3Gb/s Storage HBA: Integrated Intel P67 Controller
  • AHCI mode - Intel Rapid Storage Technology Driver 10.1.0.1008
• Operating System: Microsoft Windows 7 Ultimate Edition 64-Bit with Service Pack 1
  • No page file allocated to virtual memory

Storage Hardware Tested

The following storage hardware has been used in our benchmark performance testing, and may be included in portions of this article:

OCZ RevoDrive Hybrid RVDHY-FH-1T MLC PCI SSD (Firmware 1.15)
OCZ Vertex 3 VTX3-25SAT3-240G 240GB MLC SATA SSD (Firmware 1.15)
Seagate Momentus XT 500GB SATA SSHD ST95005620AS
Seagate Momentus XT 750GB SATA SSHD ST750LX003
Western Digital Caviar Black 750GB 7200RPM SATA HDD

Benchmark Software

• AS SSD Benchmark 1.6.4067.34354: Multi-purpose speed and operational performance test
• ATTO Disk Benchmark 2.46: Spot-tests static file size chunks for basic I/O bandwidth
• Futuremark PCMark 7: Primary Storage Suite tests real-world drive performance

Test Results Disclaimer

This article utilizes benchmark software tools to produce operational IOPS performance and bandwidth speed results. Each test was conducted in a specific fashion, and repeated for all products. These test results are not comparable to any other benchmark application, neither on this website or another, regardless of similar IOPS or MB/s terminology in the scores. The test results in this project are only intended to be compared to the other test results conducted in identical fashion for this article.

AS-SSD Benchmark

Alex Schepeljanski of Alex Intelligent Software develops the free AS SSD Benchmark utility for testing storage devices. The AS SSD Benchmark tests sequential read and write speeds, input/output operational performance, and response times. Because this software receives frequent updates, Benchmark Reviews recommends that you compare results only within the same version family.

For the purpose of testing Solid State Hybrid Drive (SSHD) products, we've concentrated more on transfer speeds and less on 4K IOPS. After running several sequential read and write benchmarks to cache the test, the Seagate Momentus XT 750GB reported consistent results that appeared to rely on hard disk performance. After ten cache tests, the Seagate Momentus XT hybrid drive continued producing a 102.26 MB/s read and 97.71 MB/s write speed.

Seagate Momentus XT 750GB Solid State Hybrid Drive

Combining two Seagate Momentus XT 750GB Solid State Hybrid Drives into a striped RAID-0 array yields much faster sequential speeds: 213.65 MB/s read and 216.77 MB/s write. These results are slight more than double the performance of a single Momentus XT SSHD, which will make our other tests much more interesting to compare.

RAID-0 Seagate Momentus XT 750GB Solid State Hybrid Drives

The chart below is sorted by total combined sequential performance, which illustrates the differences in basic read/write speeds:

In the next section, Benchmark Reviews tests transfer rates using ATTO Disk Benchmark.

ATTO Disk Benchmark

The ATTO Disk Benchmark program is free and offers a comprehensive set of test variables to work with. In terms of disk performance, it measures interface transfer rates at various intervals for a user-specified length and then reports read and write speeds for these spot-tests. There are some minor improvements made to the 2.46 version of the program that allow for test lengths up to 2GB, but all of our benchmarks are conducted with 256MB total length. ATTO Disk Benchmark requires that an active partition be set on the drive being tested. Please consider the results displayed by this benchmark to be basic bandwidth speed performance indicators.

Seagate Momentus XT 750GB Solid State Hybrid Drive

RAID-0 Seagate Momentus XT 750GB Solid State Hybrid Drives

Bandwidth speed tests begin with the Seagate Momentus XT attached to the motherboard's native Intel P67-Express SATA 6Gb/s port. Using the ATTO Disk Benchmark tool, the test drive performs file transfers ranging from 0.5 KB to 8192 KB. After several caching runs followed by restarts, the single 750GB Seagate Momentus XT revealed 115 MBps maximum read speed that plateaus from approximately 8-8192 KB file chunks, and 116 MBps peak write bandwidth plateaus from 32-8192 KB. The chart below illustrates how the Seagate Momentus XT compares:

In the next section we utilize PCMark 7 to test real-world storage performance...

PCMark 7 System Storage Test

PCMark is an objective hardware performance benchmark tool for PCs running 32- and 64-bit versions of Microsoft Windows Vista or Windows 7. PCMark 7 is well suited for benchmarking any type of Microsoft Windows Vista/7 PC: from multimedia home entertainment systems and laptops, to dedicated workstations and high-end gaming rigs. Benchmark Reviews has utilized the System Storage test suite to demonstrate simulated real-world drive performance in this article.

PCMark runs several drive tests, each with a specific purpose. Once the benchmarking tests have completed, all of the results are combined into a PCMark score, while optional detailed results illustrate actual transaction speeds. After several cache runs and system restarts, the Seagate Momentus XT hybrid drive produced its best System Storage test score of 3216 with PCMark 7:

Seagate Momentus XT 750GB Solid State Hybrid Drive

RAID-0 Seagate Momentus XT 750GB Solid State Hybrid Drives

Our tests were conducted on an Intel P67-Express Sandy Bridge motherboard using the onboard SATA 6Gb/s controller and 8x PCI-Express bus with 64-bit Windows 7. Overall results are displayed in the chart below:

Switching from synthetic to real-world benchmark tests, the next section times Windows 7 boot-up to determine how well these hybrid storage solutions cache data.

Windows 7 Boot-Up Times

One of the primary claims that Seagate makes for its Momentus XT series is improved Windows start times, which we put to the test in this section. According to Seagate, the 2nd-generation 750GB Momentus XT "can cut your system start-up time by up to 65% over a traditional HDD". Our tests allowed the system to reboot ten times to ensure O/S files were cached to the drive before testing began. To normalize our results, the timer started at the POST screen and ended when the Windows 7 desktop appeared. This removed the additional time specialized controllers added (for RAID devices), which initialized prior to displaying the POST screen.

Analyzing the results helps to show how well Seagate Adaptive Memory Technology functions, which appears to significantly improve start-up times with the new 750GB Momentus XT model over a standard hard disk drive. Two 750GB Momentus XT solid state hybrid drives assembled into a RAID-0 array matched boot times with the premium OCZ Vertex 3 SSD, but were only one second faster than a single standalone hybrid drive. One SATA-based 750GB Momentus XT SSHD processed the Windows 7 start-up routine a second faster than the OCZ RevoDrive Hybrid PCI-Express storage solution, which is impressive considering the price difference.

In the final test section, we compare real-world file transfer performance with the Seagate Momentus XT 750GB Solid State Hybrid Drive...

Compressed File Transfers

Synthetic benchmark tools are very useful, but sometimes it helps to reproduce real-world tasks; our file transfer test does exactly that. The goal of this test was to measure write time to the test drive, using three 1GB compressed files. Since we wanted to ensure our source drive was faster than all the destination drives tested, we utilized a RAM-Disk partition based on the a 4GB portion of the 16GB Kingston DDR3 installed in the system.

Each file weighed exactly 1GB (1073741824 bytes) after maximum GZip ultra compression, and three of these files were transferred from the source to destination all at once. This process was completed ten times on each hybrid drive to ensure caching algorithms were given every opportunity; however this was an unnecessary step as write-to file transfer functions are not cached. The results were consistent with every test, with the transfer time illustrated in the chart below:

Based on our results, file transfer speeds will depend on the media written to. In the case of hybrid drives that media is the hard disk, which benefits more from the integrated DRAM buffer than any logic-controlled SSD cache. The SSD performed file transfers fastest, followed by the RAID-0 combination of Momentus XT SSHDs. Beyond these two stand-out storage solutions, results were very similar.

In the next section I share my conclusion and share the final product rating.

Seagate Momentus XT Conclusion

IMPORTANT: Although the rating and final score mentioned in this conclusion are made to be as objective as possible, please be advised that every author perceives these factors differently at various points in time. While we each do our best to ensure that all aspects of the product are considered, there are often times unforeseen market conditions and manufacturer changes which occur after publication that could render our rating obsolete. Please do not base any purchase solely on our conclusion, as it represents our product rating specifically for the product tested which may differ from future versions. Benchmark Reviews begins our conclusion with a short summary for each of the areas that we rate.

Our performance rating considers how effective the Seagate Momentus XT 750GB Solid State Hybrid Drive (model ST750LX003) performs against directly competing storage solutions. In our benchmark tests, the 750GB Seagate Momentus XT SSHD delivered 115/116 MBps peak read/write speeds using ATTO Disk Benchmark, while the RAID-0 set increased bandwidth to 231/215 MBps. These results confirm that random (synthetic) benchmark tests utilize the SSHDs hard disk drive, and that tests are not buffered to the SSD cache.

When we switched to real-world tests, such as the Windows boot time, file transfer, and PCMark 7 tests, Seagate FAST Factor firmware and Adaptive Memory Technology really helped Momentus XT shine. In these tests, especially Windows boot time and file transfer, the second-generation Momentus XT SSHD outperformed the PCI-Express hybrid solution and surpassed hard disk performance. While a single Momentus XT will be sufficient for more super-users, enthusiasts can overcome limited hard disk speeds by joining two of these drives together into a RAID-0 array.

Seagate has come a long way with the Momentus series, and the benchmarks show a maturity in hybrid technology. Judging by the pace of development, it won't be long before the Momentus XT matches SSD performance in every task - not just what's cached. I'll agree that 8GB is a solid start, but eventually this SSD cache will need to grow beyond 32GB to really achieve what solid state drives can already do.

2.5" Notebook drives are low-visibility products: you see them just long enough to install and then they're forgotten. Like their Hard Disk Drive counterparts, Solid State Hybrid Drives (SSHD) are meant to place function before fashion. Anything above and beyond a simple metal shell is already more than what's expected in terms of the appearance, but unfortunately the Seagate Momentus-XT looks the part of 'strictly business'. Unlike many of the colorful brushed-aluminum enclosures we've seen for SSDs, the Momentus XT looks like most other notebook HDDs.

Construction is generally a strong point for solid state drive products, and the Seagate Momentus XT SSHD is no exception. While not quite up to the 1500-G shock resistance that most SSDs enjoy, the Seagate Momentus XT does boast a 539% higher operating shock tolerance than the WD VelociRaptor. Touting a five-year warranty helps to position the Seagate Momentus XT ahead of most other storage products, especially SSDs that often offer a basic 1-year warranty. Seagate delivers industry-leading quality and construction in all of their products, and the hybrid-performance/high-capacity Momentus XT series is the end-result of years of proven industry experience.

My value rating is going to work a bit differently than previous articles, and there's good reason for this. When this drive was originally delivered, the MSRP was set at $189. After suffering warehouse floods in Thailand a few weeks ago, that launch price then soared to $245. I've got reservations with how well the 750GB Momentus XT carries value at this new price, compared with an actual SSD. Ultimately the consumer (you) will have to make this decision for yourself.

I really like where the Seagate Momentus XT series is heading, because I firmly believe all-in-one hybrid storage solutions are the future... at least until NAND flash components can cost as much as mechanical counterparts. Multi-part hybrid solutions with 3rd party software, such as those currently promoted by the competition, are hardly a match for integrated hybrid products like Momentus XT. Now grown to offer 750 Gigabytes of storage capacity, the new second-generation Seagate Momentus XT is offering the best of both worlds better than anyone else.

Pros:

+ All-in-one Hybrid storage solution does not require software
+ Outperforms PCI-Express hybrid solutions in boot and file transfers
+ Seagate Adaptive Memory tech buffers data for SSD responsiveness
+ 5-Year full Seagate product warranty
+ Large 750GB hybrid storage capacity
+ Extremely high HDD operational shock durability
+ Supports Native Command Queuing and SMART
+ SSD Failure does not effect preserved HDD data
+ 3rd-Generation SATA 6Gb/s compliant

Cons:

- Lacks comparable IOPS operational performance to SSDs
- Expensive hybrid storage solution (post-facility flooding)
- Hard disk would benefit from 64MB DRAM buffer

Ratings:

• Performance: 9.25
• Appearance: 7.50
• Construction: 9.50
• Functionality: 9.25
• Value: 8.25

Final Score: 8.5 out of 10.

Quality Recognition: Benchmark Reviews Silver Tachometer Award.

Benchmark Reviews invites you to leave constructive feedback below, or ask questions in our Discussion Forum.

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