MySQL server is not disk bound, how do I make it faster?

[Robert Gunther]

I always assumed my server would be disk bound.

I have two servers, one with WD Red 1tb (2.5 inch) disks and another I used Seagate 1TB SSHD 1tb (2.5 inch) disks.

Neither of these are blazing vs. SSD or PCI type disks, so I assumed this would be the slowest part of my system.

I wanted to use some type of disk cache to speed things up, I have tried Fusion-IO and also PCI SSD device using Intel's Cache Acceleration Software.

The tests I have done with MySQL have showed no difference at all. None, zero, zip. I assumed the cache was just not working well in my setup.

I tried testing MySQL directly running on the Fusion-IO card, no change to MySQL performance.

The test I normally conduct is doing a DB restore. That is a real life test, repeatable and controlled. I always get the same time to restore regardless of what I am running MySQL on.

So if the disk is not my performance bottleneck, where do I look next? I am not really having any performance issues with my current workload, I just think I should be seeing greater performance if MySQL is running on a faster disk. If not the disk, something else is the bottleneck.