Gavin Hamill wrote: > 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.
PCI in general should be perfectly fine, for SDTV at least. While displaying SDTV (vdrsxfe) I see ~20% cpu use for X on AGP, ~44% on PCI (same machine, different heads, AGP is MGA450, PCI is MGA200). The huge difference is likely due to something else, like - display (X) driver (but even drivers which just memcpy the video data to the (xv) framebuffer should work on a modern machine) - PCI chipset (eg I had a VIA-based mobo, and it couldn't even keep up with SDTV on a PCI head, swapping the mobo for one w/ a real chipset made all problems suddenly disappear...) You could probably do some setpci tweaks to improve PCI throughput, but I doubt the gain would be enough (I'd expect 10% improvement or so). artur _______________________________________________ vdr mailing list firstname.lastname@example.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/vdr