Tag Archives: free

Calculate SAN Disk Performance

Need an easy, free tool to calculate disk performance on your SAN? CrystalDiskMark might be just the thing you need. Its super lightweight and runs a variety of tests with options you can choose.

How to interpret the test?

Sequential: reads/writes whatever file size you choose when you start the test sequentially. That is to say it starts writing on a sector and then writes the next part on the adjacent sector and so on. This is fastest because the head on a hdd doesn’t have to move about a lot as all the sectors are adjacent.

512k: CDM read/writes to random sectors on the drive, but it reads/writes 512KB of data at a random point, then moves to the next random point. This is faster than 4k because there’s more data read/written with less movement of the head.

4k: The same as above but instead of reading/writing the test data in 512KB ‘chunks’ it reads/writes in 4KB chunks.

4kQD32: The same as 4K but there are more requests for the data sent to the HDD controller. I’m told that some HDDs increase performance when this happens because of the way their controller logic works but I think this mostly applies to SSDs not mechanical drives.

Its a great way to see the throughput of your hardware. You can download it from here: http://crystalmark.info/download/index-e.html#CrystalDiskMark

If you found this article to be helpful, please support us by visiting our sponsors’ websites.