[psyke83]

Originally Posted by moore.bryan are any of you guys (being generic, not sexist) using the Intel graphics driver testing ppa? (https://launchpad.net/~intel-gfx-testing) like i wrote above, the fixes i described COMPLETELY fixed my choppiness in flash fullscreen. i'm VERY interested to see if it's a semi-permanent fix.

No, because that repository has no packages targeted towards Jaunty. You probably meant this one: https://launchpad.net/~xorg-edgers

I still don't get good 2D performance until I enable UXA or enable the EXA tweaks (ExaOptimizeMigration and/or the "greedy" MigrationHeuristic).

A more serious problem is that Jaunty's Xorg doesn't set the MTRR ranges correctly for Intel (and probably other) cards. This causes stuttering for video-intensive operations such as movie playback in Totem.

Verbose lspci output for my card:

00:02.0 VGA compatible controller [0300]: Intel Corporation 82852/855GM Integrated Graphics Device [8086:3582] (rev 02)
	Subsystem: Dell Device [1028:0164]
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
	Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx+
	Latency: 0
	Interrupt: pin A routed to IRQ 11
	Region 0: Memory at f0000000 (32-bit, prefetchable) [size=128M]
	Region 1: Memory at faf80000 (32-bit, non-prefetchable) [size=512K]
	Region 2: I/O ports at c000 [size=8]
	Capabilities: <access denied>
	Kernel modules: intelfb

Here's my MTRR setup:

reg00: base=0x000000000 (    0MB), size=  512MB, count=1: write-back
reg01: base=0x020000000 (  512MB), size=  256MB, count=1: write-back
reg02: base=0x02ff00000 (  767MB), size=    1MB, count=1: uncachable
reg03: base=0x0feda0000 ( 4077MB), size=  128KB, count=1: write-through

Here's what it should be:

reg00: base=0x000000000 (    0MB), size=  512MB, count=1: write-back
reg01: base=0x020000000 (  512MB), size=  256MB, count=1: write-back
reg02: base=0x02ff00000 (  767MB), size=    1MB, count=1: uncachable
reg03: base=0x0feda0000 ( 4077MB), size=  128KB, count=1: write-through
reg04: base=0x0f0000000 ( 3840MB), size=  128MB, count=1: write-combining

Enabling the write-combining range allows Totem to play 720p content smoothly on an ancient 855GM chipset.

Here's the bug report: https://bugs.launchpad.net/ubuntu/+s...el/+bug/314928

N.B. To see if you're affected, simply check your MTRR setup:

$ cat /proc/mtrr

If you don't see a range marked "write-combining", you're probably suffering from this bug as well.