The twins get a cooling upgrade
Our intrepid team of storage test systems received a rather major upgrade to Sandy Bridge hardware a few months back. More recently, we swapped their Thermaltake SpinQ coolers for a pair of much beefier Frio air towers.

These dual-fan monsters situate a pair of 120-mm spinners on either side of a heatpipe-infused radiator. The three-pin fans hang on rubber mounts to dampen vibration, and their speeds can be tweaked using a pair of in-line rheostats that offer fine-grained control. With both fans spinning at their slowest pace, the Frio is reasonably quiet. Crank them up to full tilt, and Thermaltake says the cooler will dissipate up to 220W—more than double the TDP of the fastest Sandy Bridge CPU.

Our testing methods
When briefing me on the Momentus XT, Seagate was quick to extol the drive's virtues for desktop applications, citing Dell's use of the old model in some of its business-oriented Optiplex systems. This isn't just a drive targeted at mainstream notebooks, so we have no qualms about pitting it against a wide variety of competitors that include a 3.5" Caviar Black desktop drive, a huge selection of the latest and greatest SSDs, and a handful of more direct 2.5" mobile competitors. The chart below summarizes all of the particulars of the drives involved. I've greyed out the SSDs here and in the graphs on the following pages to make things more readable—and to clearly separate a different class of products.

The Momentus XT's most direct competition comes from Western Digital's Scorpio Black 750GB, another 2.5" notebook drive with the same total capacity and 7,200-RPM spindle speed. There's no flash memory inside the Scorpio, though, and it's an older drive with less DRAM cache and a slower SATA interface. The Momentus XT 750GB's hybrid competition will come from the original 500GB version of the Momentus XT.

Although its results are shown in all the performance graphs, we're not too concerned with how the new XT fares against the Momentus 5400.4, a notebook drive that dates back to 2007. The 5400.4 will serve as our performance baseline for the value calculations that appear later in the review. It's the slowest Serial ATA drive I could find in the Benchmarking Sweatshop.

We used the following system configuration for testing:

Thanks to Asus for providing the systems' motherboards and graphics cards, Intel for the CPUs, Corsair for the memory and PSUs, Thermaltake for the CPU coolers, and Western Digital for the Caviar Black 1TB system drives.

We used the following versions of our test applications:

• Intel IOMeter 1.1.0 RC1
• HD Tune 4.61
• TR DriveBench 1.0
• TR DriveBench 2.0
• TR FileBench 0.2
• Qt SDK 2010.05
• MiniGW GCC 4.4.0
• Duke Nukem Forever
• Portal 2

Some further notes on our test methods:

• To ensure consistent and repeatable results, the SSDs were secure-erased before almost every component of our test suite. Some of our tests then put the SSDs into a used state before the workload begins, which better exposes each drive's long-term performance characteristics. In other tests, like DriveBench and FileBench, we induce a used state before testing. In all cases, the SSDs were in the same state before each test, ensuring an even playing field. The performance of mechanical hard drives is much more consistent between factory fresh and used states, so we skipped wiping the HDDs before each test—mechanical drives take forever to secure erase.

• We run all our tests at least three times and report the median of the results. We've found IOMeter performance can fall off with SSDs after the first couple of runs, so we use five runs for solid-state drives and throw out the first two. The Hybrid drives have also been subjected to five runs, but only in tests that show their performance improving after the first one.

• Steps have been taken to ensure that Sandy Bridge's power-saving features don't taint any of our results. All of the CPU's low-power states have been disabled, effectively pegging the 2500K at 3.3GHz. Transitioning in and out of different power states can affect the performance of storage benchmarks, especially when dealing with short burst transfers.

The test systems' Windows desktop was set at 1280x1024 in 32-bit color at a 75Hz screen refresh rate. Most of the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.