FYI: XBMC is slow on Xpress 1250, fast on X1650 PRO

[Toan]

On Mon, May 24, 2010 at 3:05 PM, Alex Deucher <alexdeucher at gmail.com> wrote:
> On Mon, May 24, 2010 at 2:55 PM, Toan <nguyenthetoan at gmail.com> wrote:
>> Hi
>>
>> I have a ASUS M2V-HDMI motherboard with internal ATI Xpress 1250,
>> and a PCI-E ATI X1650 PRO card. I use it as Home Theater System
>> with XBMC software. I use Ubuntu 10.04, with xorg-edger PPA
>> repository.
>>
>> If I use the Xpress 1250 graphic card, XBMC is very slow (~10-15 fps).
>> On the other hand, XBMC on ATI X1650 PRO gives 70-90 fps. FPS for
>> glxgears, however, are quite similar on both).
>>
>> For obvious reasons (less noise, less power consumption, direct HDMI
>> output), I prefer to use the internal Xpress 1250 card if possible.
>> I don't know if I setup it wrong (wrong options,....) or is it because
>> of the open source radeon driver is much better for X1650 than X1250
>> at the moment. If anyone could help me with this, i'll greatly
>> appreciate it. I'd happy to send you all the logs, ....
>
> The x1250 (r4xx-based 3D) and x1650 (r5xx-based 3D) have very similar
> 3D engines.  Most likely XBMC is making heavy use of vertex shaders.
> The x1250 does not have vertex shader hardware while the x1650 does.
> A better software vertex shader compiler can make big difference.
> Eventually you'll see better performance once the r300 gallium driver
> takes advantage of the llvm vertex shader work.
>

Thanks. That's good to know. For the moment, I guess I'll stick with Enna
Media Center instead of XBMC (I still don't want to use X1650 PRO) and
wait for the newer r300 gallium driver.