Announcement

Collapse
No announcement yet.

Radeon R600 Gallium3D NIR Backend Continues Advancing

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • SteamPunker
    replied
    Originally posted by agd5f View Post

    Sure, it just makes it harder.
    "So you're telling me there's a chance? Yeah!" (from the movie Dumb and Dumber)

    Leave a comment:


  • agd5f
    replied
    Originally posted by SteamPunker View Post
    Could those be worked around? Or avoided, by implementing only a subset of Vulkan (enough of it to be usable in at least some games, as well as GNOME and Firefox Webrender and such)?
    Sure, it just makes it harder.

    Leave a comment:


  • SteamPunker
    replied
    Originally posted by agd5f View Post

    There are 3 major challenges to supporting vulkan on pre-GCN hardware:
    1. Lack of virtual memory support
    2. Lack of memory based resource descriptors
    3. Lack of asynchronous compute queues
    Could those be worked around? Or avoided, by implementing only a subset of Vulkan (enough of it to be usable in at least some games, as well as GNOME and Firefox Webrender and such)?

    How was this handled when Vulkan support was implemented for the Intel integrated graphics in Ivy Bridge CPUs? You still see a warning on the console about Vulkan support being incomplete in that implementation, but it's not clear exactly what's missing from the spec and how it affects real-world compatibility with many games and other software.

    And how about the VC4 GPU in the older Raspberry Pis? Those are even more primitive than the AMD TeraScale era GPUs, yet someone is working on a Vulkan driver even for that.

    Leave a comment:


  • agd5f
    replied
    Originally posted by smitty3268 View Post
    I think the main limitation there is actually the ability to have virtual memory addressing, not compute shaders. That's something that was only first introduced in the 6900 cards. It's pretty unlikely anyone will add a vulkan driver just for the couple of Cayman cards.

    Although it's not clear to me if that's a hard blocker, or just an annoyance that would have to be worked around.
    There are 3 major challenges to supporting vulkan on pre-GCN hardware:
    1. Lack of virtual memory support
    2. Lack of memory based resource descriptors
    3. Lack of asynchronous compute queues

    Leave a comment:


  • smitty3268
    replied
    Originally posted by SteamPunker View Post

    Yeah, I've been wondering about that as well. It's a shame that most R600 cards (with exception of the few ones that supported FP64 in hardware) never were able to advertise OpenGL 4+ support. Looking at mesamatrix.net, FP64 softfloats support is the only thing keeping all R600-based graphics cards from fully supporting OpenGL 4.5 in Linux!
    That will come with the NIR backend being discussed in this article. I'm not sure if it's currently enabled, but I know Gert was testing it at one point. No one is adding it to the old backend.

    The other thing holding back 4.4+ support is that Khronos added additional testing requirements and the r600 driver in it's current form is unlikely to pass the certification tests. I don't know if the NIR driver backend will ever get there either, so 4.3 may be the most you can legitimately hope for out of the box. I don't know what Gert's plans are for that. If you don't care about the default, you can set a couple environment variables and it will claim support for everything - that shouldn't be a problem since no games end up actually using fp64.

    Also, it would be cool if someone with the necessary knowledge and interest would take a stab at the development of a Vulkan driver for R600 graphics cards. From what I've understood, this should theoretically be possible, since R600 GPUs support compute shaders.
    I think the main limitation there is actually the ability to have virtual memory addressing, not compute shaders. That's something that was only first introduced in the 6900 cards. It's pretty unlikely anyone will add a vulkan driver just for the couple of Cayman cards.

    Although it's not clear to me if that's a hard blocker, or just an annoyance that would have to be worked around.
    Last edited by smitty3268; 21 July 2020, 07:11 PM.

    Leave a comment:


  • SteamPunker
    replied
    Originally posted by Dukenukemx View Post
    Whatever happened to FP64 support so some of us can go beyond OpenGL 3.3?
    Yeah, I've been wondering about that as well. It's a shame that most R600 cards (with exception of the few ones that supported FP64 in hardware) never were able to advertise OpenGL 4+ support. Looking at mesamatrix.net, FP64 softfloats support is the only thing keeping all R600-based graphics cards from fully supporting OpenGL 4.5 in Linux!

    Also, it would be cool if someone with the necessary knowledge and interest would take a stab at the development of a Vulkan driver for R600 graphics cards. From what I've understood, this should theoretically be possible, since R600 GPUs support compute shaders.

    Heck, someone has been writing a Vulkan driver for the VC4 GPU in the older Raspberry Pis (everything before the Pi 4), and that GPU doesn't even support OpenGL 3! So if even that can be done, then surely it could be done for the R600 generation of graphics cards as well.

    Of course, as such older graphics cards get older and less used, there are also less volunteers out there (let alone sufficiently skilled and patient ones) to maintain graphics drivers for them. However, It would still be fun to see what these old beasts are capable of, with well-optimized modern open source drivers.

    Leave a comment:


  • Dukenukemx
    replied
    Whatever happened to FP64 support so some of us can go beyond OpenGL 3.3?

    Leave a comment:


  • sweetsuicide
    replied
    Hi, I just got my wife's formere laptop, it rocks a 6630m . I am looking forward to try out these new improvements on games. Linux is vital here, as the Windows drivers (best possible OS there is Windows 8.1) have faulty decoding, so if you're streaming, only linux will work.

    Leave a comment:


  • ms178
    replied
    Originally posted by QwertyChouskie View Post

    If your laptop has a Sandy Bridge CPU, chances are you can get an Ivy Bridge in there as an upgrade, did that on my laptop and it served my well until I finally upgraded to more modern hardware a couple of weeks ago. Just throw something like this in: https://www.ebay.com/itm/Intel-Core-...i:174280675484

    With Ivy Bridge you get HD 4000 and thus OpenGL 4. (Make sure to update the BIOS before you install the new CPU.)
    While I have disassembled that device more than enough to change the thermal paste and already swaped the CPU for a different model, I haven't tried to insert a Ivy Bridge CPU in there yet, I've read that there were compatibility issues in laptops and never dared to try it. I even run a modified HP BIOS on it already but I will start to research that topic more intensively. On the other hand, while a quad-core would be a meaningful upgrade, these are still quite expansive. And for an office machine my current CPU is good enough already (Kernel compilation takes ages though).

    Leave a comment:


  • QwertyChouskie
    replied
    Originally posted by ms178 View Post

    Unfortunately that generation of cards is not that well supported on Linux as probably AMD wasn't putting much effort in performance back then. On Linux, there were constant issues with the SB shader optimizer, OpenCL support is still at 1.1 level to this date with Clover and we are missing out on all the AMDGPU, RadeonSI and Vulkan efforts targeting GCN and newer. AMD put much more effort with GCN on Linux as it was the time they wanted to enter the HPC GPU market and needed to invest more in their Linux software stack.

    The OpenGL gaming performance on Windows was better for my 6770M originally, but even on Windows there are now a lot of issues, e.g. for my Intel HD 3000 / 6770M laptop combination you need to disable the ultra low power mode for the AMD dGPU or else you face minute long lags on the desktop - this hurts battery performance of course. And DirectX11 is not usable anymore on with current versions of Windows 10 (possibly due to detection issues as the Intel iGPU doesn't support it). So you either have to use an outdated OS (Windows 7), need to sacrifice DX11 (DX9 was fine) plus some hacks on Windows 10 or you need to sacrifice 3D performance and features on Linux but at least it does work with power savings for laptops. I chose to use Linux on that laptop and relegated it to office use only. As it gets 9 years old next month, I am thankful that it still serves me well.
    If your laptop has a Sandy Bridge CPU, chances are you can get an Ivy Bridge in there as an upgrade, did that on my laptop and it served my well until I finally upgraded to more modern hardware a couple of weeks ago. Just throw something like this in: https://www.ebay.com/itm/Intel-Core-...i:174280675484

    With Ivy Bridge you get HD 4000 and thus OpenGL 4. (Make sure to update the BIOS before you install the new CPU.)
    Last edited by QwertyChouskie; 21 July 2020, 02:26 AM.

    Leave a comment:

Working...
X