Benchmark Results: Boot Time And Game Level Loading
Wishing to translate our measured numbers into actual boot-up times, we recorded the time taken to log on and reach the Windows desktop on each device.
The Momentus XT is only marginally slower than Samsung's 830, and it's significantly faster than Western Digital's Raptor.
As you probably already know, the boot-up process is primarily a random workload involving small block transfers. So, we'll also have a look at game loading. In this exercise, we load Call of Duty: Modern Warfare 3 from the beginning of the game and monitor results at the physical device level. Our Momentus XT results were taken after the game had already been loaded three times during the previous day.
We found that the workload consists of approximately 18% random access reads and 82% sequential access reads, which, by coincidence, is almost the inverse of what we saw during the boot-up process. The average block transfer size increases to 79 KiB and the average queue depth is one.
In addition to monitoring the percentage of fast IOPS and the maximum transfer speed in MB/s, we also record the “Data Transferred/Time Index,” which is a unique metric made available by the hIOmon software. This index provides a high-level means for relative comparison of I/O performance, where "higher is better." That is, a higher index results corresponds to better performance (more data transferred and/or less response time). The hIOmon DXTI metric is calculated by taking the observed amount of data transferred by the I/O operations (converted to megabytes for scaling), and dividing by the combined sum of the observed time durations (actual response times) of the I/O operations responsible for transferring that data.
When you get right down to it, the hIOmon DXTI metric is a lot like a car's fuel economy index insofar as it conveys performance efficiency. It is comparable to more miles driven (more data transferred) for fuel used (response time taken to transfer this data). Or, similarly, the same number of miles driven (data transferred) using less fuel (lower response time).
Quite surprisingly, Seagate's Momentus XT comes out on top in the maximum MB/s transfer speed. But it loses out to Samsung's 830 on the percentage of fast IOPs and the DXTI.
The Momentus XT does much better than Western Digital's Raptor X when it comes to average read response times, landing closer to the Samsung 830.
Given relatively little time to adapt and learn, Seagate's Momentus XT is able to perform a lot more like an SSD than a hard drive. Boot times are not noticeably longer than you'd see from an SSD, and the Windows desktop is responsive as soon as it loads. Applications do realize that "snappy" SSD feel. There are inevitably occasions when the Momentus XT does feel more like a hard drive because its NAND doesn't contain the information you're requesting. In general, though, the trade-off is tolerable.