Comment 141 for bug 119730

I am having the exact same issue. It has gone away, and then come back several times since I installed jaunty. I am running the amd64 kernel on a MSI motherboard with ATI graphics. The primary hard disk works great, all the secondary ones I can read from at full speeds, but writes max out the cpu (quad phenom II) and top out at about 6 Mb/s. Very very frustrating. Problem isn't there in windows, and doesn't change if I force the drives into udma 6.