RELENG_7 jerky mouse and skipping sound (still a problem -BETA3)

Josh Carroll josh.carroll at
Wed Jan 2 08:49:49 PST 2008

> > Can you confirm that this fix helped for you?  i.e. do you still
> > see the problem?
> FreeBSD 7.0-RC1 #14: Sun Dec 30 21:50:59 EST 2007
> I'm still seeing this problem, but it isn't nearly as bad.  I still
> get some jerky mouse movement, but music doesn't skip now when I'm
> compiling.

I noticed severe sluggishness in the other day when I logged
into the console on my 7.0-RC1 box. With firefox open, the mouse was
very unresponsive, and at one point I counted and it took ~10 seconds
to register a mouse click in firefox.

The mouse jerkiness I fixed by starting moused and using /dev/sysmouse
instead of /dev/psm0.

However, the sluggishness overall in X was still there, and firefox
took a lot longer than it should to render pages. I then noticed in my
xorg.conf, I had the Depth set to 16-bit (this is on the nv
driver). I switched to 24-bit and it is MUCH faster.

I ran the wm_torture
( response test
for both 16-bit and 24-bit, and here are the results:

Test:        map_response
             MIN: 0.042016s, MAX: 0.046576, AVG: 0.044307

Test:        map_response
             MIN: 0.002540s, MAX: 0.005877, AVG: 0.004306

That's over a 10x speed up. I believe those numbers are saying with
16-bit it took an average of 44ms to draw a window, while at 24-bit it
took 4.3ms.

So, for anyone using the nv (perhaps this applies to other
cards/drivers?), check that you are not using 16-bit color depth, as
it really seems to hinder performance.

Note: this is on an 7.0-RC1 box (running ULE), so the ithread
inversion has already been included in the kernel I'm running, so that
may have helped as well. But I did not need to set FULL_PREEMPTION or
HZ to achieve the good performance.


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