In the Phoronix forums I found this post by AMD Linux's John Bridgman: "Note that the KMS performance hits are highly system-specific - eg on balance my system feels as fast or faster with KMS than with UMS.
I think the limiting factor is CPU power (ie the KMS code uses more CPU cycles than the UMS code), so it's extra important to make sure that your power management settings aren't slowing down the CPU when you need it." Also, from your XorgLog: (--) RADEON(0): Chipset: "ATI Mobility Radeon X1600" (ChipID = 0x71c5) (II) RADEON(0): PCIE card detected (II) RADEON(0): KMS Color Tiling: disabled In the same thread on the Phornix forums I found this: "KMS is slower because color tiling in DDX is disabled by default. You need to enable it in xorg.conf, see "man radeon". The man page is for UMS so it lies sometimes." The relevant section of the radeon manpage is: Option "ColorTiling" "boolean" -- [radeon driver] (regression) poor video decoding performance https://bugs.launchpad.net/bugs/578224 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
