HD Tach is a physical performance hard drive test for Windows 95/98/ME and Windows NT/2000. In Windows 9X/ME it uses a special kernel mode VXD to get maximum accuracy by bypassing the file system. A similar mechanism is used in Windows NT/2000/XP. HD Tach reads from areas all over the hard drive and reports an average speed. It also logs the read speeds to a text file that you can load into a spreadsheet and graph to visually read the results of the test.

HD Tach 3.0.4 - 8MB Tests - READ Burst Speed: (Mb/s) Points Ranking Western Digital 1TB WD1001FALS HDD 214.7 Western Digital 1TB WD1001FALS HDD (RAID 0) 277.8 Western Digital 1TB WD1001FALS HDD (RAID 1) 188.8 OCZ Vertex 2 128GB SSD 266.6 Plextor PX-128M1S SSD 143.4 Seagate 3TB Barracuda XT HDD 366.4 Seagate 2TB Barracuda XT HDD 336.4 Seagate 750GB Momentus XT SSHD 405.1 Seagate 500GB Momentus XT SSHD 231.7 Average Read: (MB/s) Points Ranking Western Digital 1TB WD1001FALS HDD 90.5 Western Digital 1TB WD1001FALS HDD (RAID 0) 150.8 Western Digital 1TB WD1001FALS HDD (RAID 1) 90.7 OCZ Vertex 2 128GB SSD 243.7 Plextor PX-128M1S SSD 103.4 Seagate 3TB Barracuda XT HDD 137.3 Seagate 2TB Barracuda XT HDD 115.5 Seagate 750GB Momentus XT SSHD 95.9 Seagate 500GB Momentus XT SSHD 89.4 Random Access Time: (ms) Points Ranking Western Digital 1TB WD1001FALS HDD 12.1 Western Digital 1TB WD1001FALS HDD (RAID 0) 12 Western Digital 1TB WD1001FALS HDD (RAID 1) 10.1 OCZ Vertex 2 128GB SSD 0.1 Plextor PX-128M1S SSD 0.3 Seagate 3TB Barracuda XT HDD 16.7 Seagate 2TB Barracuda XT HDD 17 Seagate 750GB Momentus XT SSHD 0.4 Seagate 500GB Momentus XT SSHD 17

HDTach tests burst speed, a measure of how fast the system can transfer information from the hard disk to RAM. Thanks to the 64MB of onboard cache, the 2TB Seagate Barracuda XT HDD achieves a burst speed of 336.4 MB/s - very good for a four platter / eight head mechanical drive. The average read is measured at 115.5MB/s.