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RV350, compositing and horrible performance.

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  • oliver
    started a topic RV350, compositing and horrible performance.

    RV350, compositing and horrible performance.

    Hey all,

    I probably best ask some opinions here, before bombarding the ML with this.

    I have an ancient laptop, that's still going strong. An IBM T42. This is a 2004 model. It spurts a fast 2.1 GHz Pentium-M and boasts a whopping 2 GiB of ram. There's a pretty fast 32 GiB SLC IDE-SSD in it and the onboard GPU, a Radeon 9600, features 64 MiB dedicated videoram. While yes, it's almost 10 years old, it works really well and runs pretty fast/fast enough.

    Last week I've updated to Ubuntu Gnome 13.04 which features Gnome 3.6 that I upgraded to 3.8. All works well, except I find the video performance appalling. Now I understand very well that it is very old, and r300 architecture is quite dated. I also was able to play 3D games on it (a heavy 3D game via wine for example does about 7-15 FPS, but it worked well) before.

    With the new Gnome the desktop is supposedly fully hardware accelerated (e.g. composited). However things are just really slow, with the CPU sitting at its low ondemand setting mostly, so it's not the CPU being over stressed. Things like opening the 'dash' or is it 'activities' I believe it's called? takes almost 1 to 2 seconds to render. Alt-tab is also equally slow. Dragging a window around however seems fast enough.

    So where to start looking, or is the rv350 really that old that compositing desktops sucks, while 3D applications work fine. Personally I'm more thinking of blaming Gnome, since I think even 3.6 doesn't work composited on ati blobs on more recent hardware, but maybe there's something else amiss.

  • timothyja
    replied
    Originally posted by agd5f View Post
    First try a newer kernel and version of mesa. There have been a lot of performance improvements in 9.1 for example.
    I have already tried a new kernal/build of Mesa as I wanted to see if Vadim's shader optimizations would help my issue but they didnt seem to help at all.

    Originally posted by agd5f View Post
    Also try adjusting the CPU governor as per other comments in this thread.
    I will try this out later today.

    Originally posted by agd5f View Post
    For the ttm defragmentor, see drivers/gpu/drm/ttm/ in the kernel source.
    Thanks.

    Leave a comment:


  • agd5f
    replied
    Originally posted by timothyja View Post
    I seem to have the same issue on my RV620 not with the desktop but with games that dont seem to be all that graphically intense.
    Are you able to gives some more details on where exactly one would look to start inplementing a ttm de-fragmenter? I'm not sure if I'm up to the task but it does sound interesting and I would be keen to at least have a look around.

    Thanks for your time.
    First try a newer kernel and version of mesa. There have been a lot of performance improvements in 9.1 for example. Also try adjusting the CPU governor as per other comments in this thread. For the ttm defragmentor, see drivers/gpu/drm/ttm/ in the kernel source.
    Last edited by agd5f; 05-09-2013, 09:36 AM.

    Leave a comment:


  • agd5f
    replied
    Originally posted by Ray7brian2 View Post
    It likely uses some cpu fallback. How to check that, I have no idea
    Gallium doesn't support software fallbacks. The driver may still be doing something inefficiently however.

    Leave a comment:


  • timothyja
    replied
    Originally posted by agd5f View Post
    What is your question? vram has much better bandwidth compared to system memory from the GPU's perspective so in most cases it's preferred to store buffers in vram. If we don't have enough vram to cover all the requirements, we may end up with thrashing. There's probably room for improvement with respect to the heuristics used to decide which pools we allocate from and whether we migrate or not. A ttm de-fragmenter would probably also be helpful. Either of these are good projects that don't require low level GPU specific knowledge and could provide nice performance improvements.
    I seem to have the same issue on my RV620 not with the desktop but with games that dont seem to be all that graphically intense.
    Are you able to gives some more details on where exactly one would look to start inplementing a ttm de-fragmenter? I'm not sure if I'm up to the task but it does sound interesting and I would be keen to at least have a look around.

    Thanks for your time.
    Last edited by timothyja; 05-09-2013, 03:48 AM.

    Leave a comment:


  • Ray7brian2
    replied
    It likely uses some cpu fallback. How to check that, I have no idea


    Leave a comment:


  • smitty3268
    replied
    Originally posted by duby229 View Post
    I remember when the first PCIe cards were released just about every review I read said the bandwidth was orders of magnitude overkill. That much bandwidth simply could not be utilized.
    It depends on the card - newer ones will show improvements even going from PCIe2 to PCIe3, at least in certain tests. At the time, I don't think anything was maxing out AGP8x, but manufacturers knew that those cards were coming.

    Leave a comment:


  • agd5f
    replied
    Well, ideally, you want to minimize the amount of traffic going across the bus. If you have to migrate a lot of data back and forth, you've already lost.

    Leave a comment:


  • duby229
    replied
    I remember when the first PCIe cards were released just about every review I read said the bandwidth was orders of magnitude overkill. That much bandwidth simply could not be utilized.

    Leave a comment:


  • agd5f
    replied
    Originally posted by oliver View Post
    I did figure as much, but just wanted to double check.

    AGPmode=4 does FEEL faster Won't AGPmode affect memory bandwith from/to the card? E.g. when swapping via gart?
    In theory yes, in practice it doesn't really make a lot of difference.

    Leave a comment:

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