HD Tach is a physical performance hard drive test that uses a special kernel mode VXD to get maximum accuracy by bypassing the file system.

The HD Tach sequential read test is a little bit different from other benchmarks. Most benchmarks create a file on the hard drive and test within that file. The problem is that modern hard drives use a zone bit recording technique that allows different read speeds depending on where the data is located. Data on the outside of the drive is much faster than data recorded on the inside. Obviously for SSD this is not an issue. We see a sequential average read burst speed of 120 MB/sec and sequential read speed of a near 160 GB/sec. Higher is better of course.

In addition to sequential read, HD Tach tests the drive's random access time. Random access is the true measure of seek speed. Many drives advertise sub 10 millisecond seek speeds, but seek speeds are misleading. Also again, without a head that needs moving around, the SSDs are just soooo fast as they have no mechanical moving parts. Here obviously .. the smaller number means better.

Note - currently the development of this benchmark has been halted. In order to do HD-Tach write tests we need to register the software, which isn't possible any longer. The developers do not respond to their phone & emails either. If you have a registered version of HD Tack 3.0.4.0 and would like to share it, please contact us.

SiSoft Sandra HD test

Let's do a very synthetic test with Sandra, just to see if we can match the results we've seen in ATTO.

We first look at Random access time, the lower the better. Since the SSD does not have a head to mechanically move around, the OCZ Core SSD had an access time of well below <1ms where the traditional HDDs range between 8 to 14ms.

What SANDRA also does (important for a HDD) is to test at several positions of the HD. See, at the inner part of a platter the performance is slower. The drive Index test is what I refer to. The higher the better. The Samsung Spinpoint (5400 RPM) averages at 44 MB/sec. The Maxtor 200GB (7400 RPM) at 47 MB/sec. The WD Raptor is real fast at 70 MB/sec and then the OCZ SSD shows brilliant performance up-to 116 MB/sec speeds. But then the SLC NAND based memory kicks in at the Silicon Power product, an amazing 175 MB/sec read speed was achieved.

Subjective tests

Standard procedure for our HDD/SDD tests is to make a clean install of Windows Vista on the SSD drive.
Playing some games .. work a little on it, just basic normal PC usage. And I just have to admit I like it.

Really fast access times versus good speed and no noise. What's not to like? Surely there's a slowdown every now and then, especially in small writes. yet You get that stuff with a traditional HDD just as well.

Very noticeable is system bootup-time; Windows Vista boots up in 18 to 20 seconds, which typically is a minute maybe two on an average HDD based system. Though in all fairness, the SSD Vista installation was fresh and clean.

For you as a gamer I did a subjective test as well. Call of Duty 4. Starting up the game and load times feel just so much faster.

• On the Raptor is takes 22 seconds to startup the Ghilly suit level
• On the OCZ SSD is takes 12 seconds to startup the Ghilly suit level
• On the Silicon Power SSD it takes 9 seconds to startup the Ghilly suit level

Impressive to say at the least. Again, this is a subjective 'real-world' test. Numbers might and likely will differ in different environments / PCs.