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.

HDTach shows that SLC SSDs are faster, yet when we compare the MLC OCZ Core and Gskill drives again the Gkill SSD takes a lead and positions itself on a sturdy second place.

We measure a sequential average read burst speed of 130 MB/sec.

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 is better.

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 HDTach.

What SANDRA also does (important for a HDD) is to test at several positions of the HD. See, at the outer 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 fast at 70 MB/sec and then the OCZ SSD shows brilliant performance up-to 116 MB/sec speeds.

The SLC NAND based memory kicks in for the Silicon Power SSD at an amazing 175 MB/sec read performance. Second place goes to the G.Skill drive. at 160 Bucks .. that's quite nice really.

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, combined with good speed and no noise: What's not to like? Sure 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 17 to 19 seconds, which is typically a minute (maybe two) on an average HDD based system. Though in all fairness, the SSD Vista installation is new and thus 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 G.Skill SSD it takes 8-9 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.