Talk:Frame display timing

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The most important effect of bad display timing is juddery video - ie., CNN's news ticker not displaying smoothly. Tearing shouldn't be that much of an issue since a lot of the popular video cards prevent tearing from occuring in the driver.

The rtc timeing on my system is diffrent to that listed. I presume this has changed in a kernel version.

myth ~ # cat /proc/sys/dev/hpet/max-user-freq
myth ~ # echo 1024 > /proc/sys/dev/hpet/max-user-freq
myth ~ # uname -r


I'm not an expert, but i think that hpet replaces the rtc clock. But hpet provides an rtc emulation (read: rtc compatible API with hpet code). Since it is a "kernel inside" thing, there are not a lot of docs around here.

To me, the best idea would but to set hpet and rtc users freqs boths, since these variables are independant in the kernel. But while rtc is emulated but hpet, i bet that rtc clock must be slower or equal than hpet one.

so i'd would so :

sudo sysctl dev.hpet.max-user-freq=1024
sudo sysctl dev.rtc.max-user-freq=1024


echo 1024 | sudo sh -c "cat > /proc/sys/dev/hpet/max-user-freq"
echo 1024 | sudo sh -c "cat > /proc/sys/dev/rtc/max-user-freq"

or (and the best solution to me) add configuration these lines in sysctl.conf



Is there a way to use RTC for timing when GLX is enabled? I would like to still use XvMC (which for Openchrome/VIA requires GLX/DRI/DRM) and OpenGL menus. By using OpenGL for rendering does this cause problems?