Hard Drive Test Information

Hard Drive Benchmark results (“Baselines”) were gathered from users’ submissions to the PassMark web site as well as from internal testing. PerformanceTest conducts three different tests and then averages the results together to determine the PassMark Disk Mark for a system.

Three standard tests have been defined:

Disk Sequential Read

A large test file is created on the disk under test. The file is read sequentially from start to end. On most systems the file size is 200MB and the default test duration is 20 seconds. Reading is done without caching by the operating system, in an asynchronous fashion, with an I/O queue length of 20 and with each read operation being for 16KB. During the test period the file is typically read several times sequentially. Note that certain O/S features like file system compression, and settings in the PerformanceTest preferences window can alter the file size and test duration. The result is reported in MBytes/sec.

Disk Sequential Write

A large file is written to the disk under test. The 500MB file is written sequentially from start to end. Test conditions are otherwise the same as the read test.

Disk Random Seek RW

A large test file is created on the disk under test. The file is read randomly; a seek is performed to move the file pointer to a random position in the file, a 16KB block is read or written then another seek is performed. The amount of data actually transferred is highly dependent on the disk seek time.

Disk Mark

This is the number reported in the benchmark charts. It is an straight average of the three values above. The average is then scaled up by multiplying the average with a 'magic' number, which is 10.85 in V7 of PerformanceTest, in order to make the number larger. The larger number is better when it comes time to combine all the mark values to form the system's PassMark rating.