This is not my memory of how it used to behave, but it's been a long time since the machine has been regularly used for I/O intensive work. Especially if this is a change, I would check out the disks with dd to measure speed, and run smartctl from smartmontools. My best guess is that you are suffering hardware failure and your disks are being wicked slow. run 'systat vmstat' under load and watch the operations/second. You should be seeing at least 100 transfers/second under build.sh type workloads with 100% busy. I have a 2.4GHz box with 5-year-old disks and I think get that. But if it's 100% busy and 6 you probably have a troubled disk. My guess is that this is not about the piixide being in compatibility mode. Definitely time for full backups right now.
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