Running FC4 64 bits, I found that performance is worse when 1 processor is under load than when both are under load. For example, a "bzip2 somefile" takes 310 sec to complete when 1 processor is under load, but it takes only 165 sec to complete if the other processor is busy at the same time. This problem persists for the default FC4 kernel and the most recent one, and also for a 2.6.14-rc3 kernel. Based on various hints I found through google, I have tried kernels with and without powernow, various settings for power management, and different settings for ACPI (either compuled into the kernel or as kernel options) but so far I have not been able to get the same performance when only 1 CPU is under load. Does anyone have an idea what I could try next, or, better yet, has anyone had this problem as well and managed to fix it?
I have a GA-K8N Ultra-9 motherboard with an AMD Athlon 64 X2 4400 processer, 2 Gb memory.