Re: [Dri-devel] R200: Why is SW TCL faster?

[Jorge L. W. <jo...@cs...>]

> IIRC this came up in a discussion with Michel D=E4nzer and someone else
> some months ago. I noticed that glxgears was slightly faster without TC=
L
> on my Radeon 7500. We argued that TCL means that the graphics card has
> to do more work and the CPU less. If your CPU is not otherwise occupied
> you can get higher framerates without TCL as the work is sort of shared
> by CPU and graphics card. You should also notice a higher CPU
> utilisation without TCL.
>
> If you get big differences in frame rates it may be something else,
> though.
>

Well, I don't know if I'd call them big differences but they seem
significant. In atlantis (800x600) for example:


HWTCL 354.9 fps
SWTCL 436.6 fps
ATI   436.6 fps


Where ATI is the x4.3.0 drivers found here:=20
http://www.schneider-digital.de/html/download_ati.html



In gears (800x600) the diffrence between HWTCL and SWTCL are less notcibl=
e
(I used top to get the idle times).


HWTCL 235.8 fps 96-97% idle
SWTCL 235.6 fps 92-93% idle
ATI   394.3 fps 0% idle (??)


This all seems very weird to me. Could it be that there are cases where
using HWTCL just isn't worth it?


jOrGe W.