[Dri-users] Baffled by Savage DRI performance?

[Robert S. K. <rs...@ds...>]

Hi,

I have a box on which I run MythTv (a homebrew PVR app).  I recently 
upgraded my xserver to use the DRI.  DRI is definately enabled, my 
glxgears count went from ~130fps to ~500fps & glxinfo reports direct 
rendering enabled.  However I'm seeing issues now with the performance 
under MythTv and in several other, seemingly unrelated areas.  In 
general, the issue I see is that when I drag windows around the screen, 
or under Myth, when I play video, I see a spike in my Xserver's cpu 
utilization.  Comparing with before I installed DRI, my Xserver %CPU is 
several times higher than previously reported.  (30-50% where previously 
it never broke 10%).

I'm using FC3 (2.6.10) with the CVS DRI code.  My machine is an Athlon 
XP 2400 with 512Mb ram and an on board ProSavageDDR chip.  This MB uses 
shared system memory for the graphics card.

I've tried several different sets of compiler flags with no apparent 
effect, I've looked up and down the config files for X, Mesa, and the 
DRM for debug flags, compiler optimizations, etc. all to no avail.  I've 
set the AGPSize & AGPMode options in my server appropriately.  I've also 
tried both settings for BCI for Xv.  I'm at a loss as to what might be 
causing this loss in performance. 

When rendering video, MythTv is admittedly a memory BW hog.  It also 
uses Xv to scale the video.  (Xorg.0.log reports hardware Xv scaling is on)

I've seen some discussion recently on the users list about DRM and the 
savage driver.  Is it possible that the stock Xserver driver enables DRM 
for areas that the shiny new one doesn't?

If not, are there any options in my config files that I should take a 
look at for ideas?

Thanks in advance,
Rob