I had an 890fx board and I found the performance was much slower than my Intel P45 based board (with a single drive). So slow in fact that I ended up building a 3 drive raid 0 to get around the performance problem on the AMD platform. This gave me about 150% of the performance of a single drive on the P45. I then moved to X58 and kept the raid array which further increased the performance.
This was all on my server (listed below) I use the space as a temp and scratch location for new data, the AMD system really pissed me off because of the hdd performance! In fact it was a great reason to put my X58 into the server and upgrade to X79
If you are looking at getting new gear and are hdd bound, I would suggest staying with Intel.