Hi all,
Over the last days, Thomas and I have been trying to sort out why my nearly-identical machine couldn't run his VGA sync patches properly.
The key difference is my Radeon 7000VE is PCI, whilst his is AGP. I tried the PCI Radeon in two old Pentium-3 era machines, and on my modern Pentium D930 desktop, all with the same behaviour - fullscreen video over PCI causes huge CPU usage in the Xorg process, even when using xv 'acceleration'.
When I switch the PCI Radeon for a PCI Express X300 (the very lowest 'X' series you can get), everything is glorious: Xorg CPU use is barely 1%.
Unfortunately I don't have any machines with both AGP and PCI on which I can try the same OS image but we both think it's safe to conclude that PCI is just unsuitable for this task.
Many thanks to Thomas for writing the patches in the first place, and also for the time he's spent logged into my machine remotely trying to solve the problem!
Cheers, Gavin.