|SSD Benchmark Tests: SATA IDE vs AHCI Mode|
|Articles - Featured Guides|
|Written by Olin Coles|
|Friday, 16 April 2010|
Page 2 of 13
SSD Benchmark Differences
Solid State Drive technology comes in a myriad of shapes and sizes, which is to say that no SSD is the same as the next. This is why Benchmark Reviews has used three different SSD processor for this article, and did not focus on only one. These differences extend to the strengths and weaknesses of each SSD processor, which might translate into better IOPS performance or bandwidth speed, but could also include new features such at native encryption or TRIM support. Just as every SSD is unique, so is every benchmark testing tool.
As Benchmark Reviews would later discover, our singular use of the HD-Tune software to measure operational IOPS performance was a mistake. HD-Tune 4.01 works fine for measuring sequential read and write bandwidth speeds, but it's a single-threaded application that doesn't issue parallel requests in random IOPS tests. Our previous results relied on this tool to help shape our conclusion of AHCI vs IDE performance, but after some additional testing we determined a second and third opinion were necessary.
For this article, Benchmark Reviews has included results from CrystalDiskMark 3.0.0b and AS-SSD Benchmark 1.4.3704 to help compliment benchmark speed tests from HD-Tune. These tests should offer a more concise report, and assist PC hardware enthusiasts on choosing the SSD and SATA controller mode that is best for their needs.
AHCI & IDE SATA-Mode Differences
Most desktop computer motherboards offers hardware enthusiasts the option to adjust the SATA controller interface settings in their BIOS between AHCI and IDE mode. Traditionally, IDE is the time-tested standard for desktop hard drive products. The IDE interface offers basic control over the storage device, but unfortunately it does not include enterprise-level features. Advanced Host Controller Interface (AHCI) on the other hand, was created as a means to deliver additional storage support for server backplanes and high-end performance desktop computers.
Between these two disk IO settings, there are a few specific features that differ. AHCI-mode includes hot-swap drive support and Native Command Queuing that is not available in IDE mode. IDE does not support RAID arrays, and does not include the extended power management features that AHCI offers. For OpenBSD servers, port multiplier support is also enabled through AHCI.
Bandwidth Speed vs Operational Performance
The argument between AHCI and IDE SATA-modes revolves around two other dynamics: bandwidth speed (MB/s) and operational performance (IOPS). The two metrics work together, but one is more important than the other. Consider this analogy: bandwidth determines how much cargo a ship can transport in one voyage, and operational IOPS performance 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.