Stuttering / Frame drops with RS880/785G and AMD Bulldozer CPU

[Shahar Or]

2012/2/15 Shahar Or <mightyiampresence at gmail.com>
>
> 2012/2/14 Michel Dänzer <michel at daenzer.net>
> >
> > On Mon, 2012-02-13 at 13:05 +0200, Shahar Or wrote:
> > >
> > > A Live image of Ubuntu Desktop 12.04 amd64 was also tested. It had the
> > > same stuttering / framedrop.
> >
> > Have you tried a live image of a different distro?
>
> I've tried openSUSE-12.1-GNOME-LiveCD-x86_64.iso. Same thing. Maybe a
> bit worse. Using the 'performance' governor results in no stuttering,
> just like in Ubuntu 11.10 (more on that below).
>
> > > 2012/2/9 Michel Dänzer <michel at daenzer.net>
> > > > On Don, 2012-02-09 at 02:03 +0200, Shahar Or wrote:
> > > So I ran sysprof, which is an easy GUI and to my content I only needed
> > > to press a "Start" button :). That's when the magic happened. From the
> > > moment it starts the stuttering goes away. Sweet rendering smoothness
> > > of divine electrical display benefaction ensues! And from the moment I
> > > press "Profile" to stop it, it stops and stuttering returns OMG. And
> > > this is perfectly persistent. What does this mean?
> >
> > Not sure...
> >
> > Which cpufreq governor is being used? Assuming it's one that dynamically
> > changes CPU core frequencies, such as ondemand or conservative, does the
> > problem go away if you switch to one that doesn't, e.g. performance or
> > powersave?
>
> This is fun.
> performance: smoothness goodness
> ondemand: the stuttering as demonstrated in the video
> conservative: stuttering reduced to seemingly about 10% compared to ondemand
> powersave: stuttering increase seemingly to about five times more than
> with ondemand
>
> When using ondemand, raising minimum frequencies results in less
> stuttering. Raising the minimum frequency of all four cores to the
> second step, 1.7GHz, helps a lot and and raising it to 2.5GHz results
> no stuttering. This is under the limited strain of dragging windows
> around in 1280x1024 in compiz, Ubuntu 11.10.


Dear Michel, list,
Is there anything else I can do in order to help diagnose this issue, please?

Here is sysprof:
http://paste.ubuntu.com/851535/

Perhaps this is something with cpufreq that's working incorrectly? It
seems unrelated to the GPU. I also get these stutterings at the
virtual terminal.