Disk Drive Controller
The system drive controller is an important part of system performance. In most modern boards your drive controller will run off of the PCI-e bus. The PCI-e bus performance can be affected by poor trace layout as well as many other design choices that show up on different boards.
For testing we use Sisoft's Sandra and Everest.
Oddly enough our Sandra numbers for HDD performance appear to be backwards. We see that the stock performance is right in the middle, while the HDD performance with the HD 5870 installed takes a step back and the overclocked HDD performance drops way behind. We see the same pattern with the USB 3.0 speeds. This could be an issue later in our testing.
Even more interesting. Everest shows us something completely different. Instead of dropping in performance between stock and overclocked states we see a slight increase.