Resizeable BAR support issues

Discussion in 'Videocards - AMD Radeon Drivers Section' started by Espionage724, Nov 26, 2020.

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  1. GhostXL

    GhostXL Ancient Guru

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    Have this Enabled on my ASUS Crosshair VII HERO X570. Have the 6800 XT but not the 5000 series yet. Still can't find a 5900x that isn't on ebay or another reseller marked up double by scalpers.

    I haven't noticed anything too extreme, but I haven't a method to test either. I do see some loading times improved but not sure if its because of Resizable BAR and Above 4G encoding or not. Either way both are enabled and running, no glitches, no mess, no downwards performance issues.
     
  2. somemadcaaant

    somemadcaaant Master Guru

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    Enabled BAR yesterday (Gigabyte B550 AORUS PRO AX) since having the card for about a week, experienced a couple of loading crashes with one game Killing Floor 2 with some visual lines running down screen, a game restart fixes the problem, doesn't seem to like the game too much. Will be trying some fresh configs in case of Nvidia left overs.

    Loading of some games seemed improved for Dying Light, Rising Storm 2, will be trying more newer games.

    The new AMD setup has been like a breath of fresh air with the new BIOS options and ease of use (PBO)/Radeon software/features over all, been quite fun to play with and tweak. Glad I waited this long to upgrade my old stale 5930K + 1080 :rolleyes:
     
  3. Astyanax

    Astyanax Ancient Guru

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    crashes are probably the agesa itself.
     
  4. RaulR

    RaulR Master Guru

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    I have a MSI x470 Gaming Plus Max with a Ryzen 2700x and a RX 5700 XT. I have installed the latest Beta BIOS with support for Re-size Bar. MSI have very brief release notes for their BIOS, and they weren't very clear on this so I don't understand, I know it's a feature supported by Ryzen 5000 cpu's and RX 6000 gpu's, but then some people on forums say you can enable for other generations also?
    I enabled Above 4G and Re-size Bar but the BIOS locked and i had to reset it.
     

  5. Astyanax

    Astyanax Ancient Guru

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    Zen 2 and 3 only, no support for 1 and +
     
  6. inouext

    inouext Member Guru

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    Ryzen 7 1700 Pro / RX 580
    Biostar B450 Agesa 1.1.0.0 PatchD
    I can enable both on bios, how can i make some benchmarks to see if it is working on gen1?
     
  7. JonasBeckman

    JonasBeckman Ancient Guru

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    https://www.reddit.com/r/Amd/comments/kqynbq/psa_how_to_enable_sam_on_vega5664_and_why_its_not/

    Interesting, so the earlier AMD driver could possibly work on current bios versions for ReBAR+SAM but then it got locked to 6000 series only. (Continuing that trend I guess. ~ )
    Plus some test results on Vega here and some observations, could have issues or could be some other bottleneck think MSAA works better in Navi10 and 20 but Vega should also not be as badly bottlenecked though it still takes more out of the GPU as I remember.

    Could be useful for testing for anyone interested you essentially just need the earlier November driver and then testing some game like Forza or Valhalla where a higher performance gain can be observed with the correct bios options for ReBAR and that should confirm if it's active or not although the full debugger and going into how much the GPU is addressing certainly answers whether or not it's active. :D

    EDIT: But yeah the extended memory range in the device manager for the Re-Sizable BAR mode being active and then with a non-locked driver (20.11.1) then if it's not 256 MB chunks SAM is active and working.

    Or just look at the performance figure I suppose easier with one of the games reported to show above average results but it should also confirm whether the full thing is active.
    (Driver actually utilizing this feature or not.)


    EDIT: And while driver software locking isn't fun AMD might have had some actual reason here for limiting it to the 6000 series only for now if there are unexpected behaviors or other inconsistencies or issues with older GPU models.

    Or it could just be limited to the 6000 series for the purpose of moving hardware and having it as a fancy feature same as the earlier AMD 5000 series CPU support which then got relaxed.

    Should be lifted once NVIDIA is satisfied with their own testing and start unlocking it for their GPU's in newer drivers I would think, have to compete where they can after all especially giving a nice advantage to the competition with D3D12 or Vulkan should see this opened up for additional graphics cards unless there's some serious issue in doing so that needs to be resolved or acknowledged preventing it from being implemented for some of the older GPU models.



    EDIT:
    https://www.phoronix.com/scan.php?page=news_item&px=RADV-Mesa-21.0-SAM

    So yeah 2 - 3% it seems so on average it's a small increase but that's still a gain. :)
     
    Last edited: Jan 5, 2021
  8. VinZe

    VinZe New Member

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    Hi,

    Also having a issue with B450 Tomahawk Max. After enabling 4G/Re-size BAR in BIOS the computer doesnt boot, monitor says cant detect output. Works again after resetting CMOS. 3600x and Vega 56.
     
  9. Espionage724

    Espionage724 Member Guru

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    In my case with 20.11.1, VRAM reporting is broken. Computer boots, and D3D11 games seem fine, but anything Vulkan has issues. This is with a RX 580/Polaris, but does Vega do something different?
     
  10. Astyanax

    Astyanax Ancient Guru

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    only works with CSM off in a pure uefi mode.
     
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  11. VinZe

    VinZe New Member

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    Thank you, after that change its working now.
     
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  12. Undying

    Undying Ancient Guru

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    You did manage to enable it with 2700x and rx580?
     
  13. Eastcoasthandle

    Eastcoasthandle Ancient Guru

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    https://old.reddit.com/r/Amd/comments/kr6z9h/smart_access_memory_on_my_3600_5700_xt/

    I haven't been following this thread however an AMD engineer is. And I found out through reddit.


     
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  14. JonasBeckman

    JonasBeckman Ancient Guru

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    Interesting but now we're also back to where this full performance Zen3 feature (Done in software through firmware on Zen2 and earlier, much slower than hardware.) apparently does feature into whatever AMD is doing with SAM in addition to Re-Sizable BAR support and extended address ranges with Above 4G Decoding active.

    Hmm well it is certainly possible that AMD has used these extensions for some form of texture optimization (Swizzles? I'm not too good at this stuff as is apparent.) but I thought it was mostly debunked well that is until now at least.

    EDIT: PDEX/PEXT
    https://github.com/dolphin-emu/dolphin/pull/9233


    EDIT: It does in a way answer how some of the games are seeing above average performance results and even in Linux and the code there you get the same 2 - 3% gains if AMD's utilizing some extra optimizations though I am not sure if the games are coded with this in mind or if it just happens because of a ton of data being moved through here. :)

    Sigh it's a bit more complicated whether it's shifting through (Oh yay trying to get this correct.) PCI-E bandwidth and the rest of the system. (CPU and RAM.) or the GPU and VRAM.

    Having the ability to map out and use a much larger range effectively I think almost all the GPU's VRAM ("up to") you overcome the PCI-E bandwidth limit in these cases.


    Could be why games like Forza and Valhalla sit at close to a 10% gain whereas the titles where it mostly keeps to VRAM you have a different bottleneck but it can still see small gains so there's the 2 - 3% even for Vulkan or D3D12 which overcome other bottlenecks like AMD's D3D11 multi-threading limitations.


    EDIT: Curious if this can be stacked on top of Hardware GPU Scheduling getting a 3 - 6% total. :D
    (Averaged out and later on as this is turning into a standard further gains can be had though by then as this is standard it'll just be there, ideally ha ha.)

    Overcoming older or "poorly" set up newer systems with CSM+MBR instead of UEFI+GPT is probably the current issue, I've been on GPT since the previous system almost a decade back so I had no idea MBR was still so prevalent but there has to be a reason for it either OEM practices or lack of care when doing a disc or ideally USB OS install and the settings this would be utilizing on default if you're not careful.


    Converting is possible though it's not a insurmountable challenge format and re-partition lose all data kind of deal although before engaging in that you should at least back up important stuff just in case. :)



    EDIT: And yeah AMD doesn't support H-GPU Scheduling (Yay a worse acronym than HAGS ha ha.) so no SAM HAG combo just yet.
     
    Last edited: Jan 6, 2021
  15. JonasBeckman

    JonasBeckman Ancient Guru

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    Pretty certain PCI Express 3.0 should also be good long as this is supported well, game engines are kinda conservative most of the time (Baring any ridiculously over the top texture packs or "Ultra" over the top settings and such.) when it comes to RAM and VRAM utilization preferring around a 2 - 4 GB utilization with a few newer games and engines pushing this more and also using more PCI-E bandwidth and all the data going around or how to simplify that.

    Shouldn't be any major bandwidth issues from pushing bigger chunks around I mean, long as AMD and NVIDIA support older GPU models and the motherboard hardware for AMD and Intel and their processors in how this is utilized now for AMD and the 6000 series GPU's and soon also for NVIDIA and what their initial support will look like, expecting it to be focusing on Ampere but I would imagine Turing and Pascal at least to also be supported they're popular and an extra ~5% performance would be useful if nothing else than for competition and benchmarks against AMD and then from AMD and their support if possible for RDNA1 and GCN5 so the 5000 series, Vega and Polaris I would think at least.

    We'll see I suppose. Competition is doing good here even if it's just from AMD and NVIDIA trying to maintain or get a bit of a edge or advantage in these performance results ha ha. :D
    AMD starts supporting this and then NVIDIA also supports it and even Intel is now in on it yeah working well I'd say, consumers getting an extra performance boost isn't a bad outcome here.
     
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  16. Astyanax

    Astyanax Ancient Guru

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    That RTG engineer is full of horsecrap.
     
  17. RaulR

    RaulR Master Guru

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    OK, so i managed to enable both Resize-bar and Above 4G, on my MSI x470 Gaming Plus Max using the latest beta BIOS posted on their support page.
    Large memory range is enabled.
    https://ibb.co/gV9fTv3

    So i tested some games with both above 4g/resize bar on and off.
    CPU is Ryzen 2700x, 32 Gb Ram @ 2933, GPU RX 5700 XT.

    Resize Bar ON:
    AC Odyssey, 1920 x 1080: 56 fps, 2560x1440: 56 fps, 3200x1800: 45 fps.
    https://ibb.co/B3wNH7G
    https://ibb.co/HFpRG98
    https://ibb.co/6sJ7Dg5

    Strange Brigade, Vulkan API, 1920x1080: 168 fps, 2560x1440: 121 fps, 3840x2160: 72 fps.
    https://ibb.co/4V6rrsX
    https://ibb.co/jRyWD65
    https://ibb.co/YBCT8Yn

    Horizon Zero Dawn, 1920x1080: 85 fps, 2560x1440: 70 fps, 3840x2160: 38 fps.
    https://ibb.co/V0GBBrT
    https://ibb.co/NLQBXgT
    https://ibb.co/drVss6Y


    Resize Bar OFF:
    AC Odyssey, 1920 x 1080: 56 fps, 2560x1440: 56 fps, 3200x1800: 47 fps.
    https://ibb.co/v389dYV
    https://ibb.co/CmVyXGR
    https://ibb.co/5KJ5qw1

    Strange Brigade, Vulkan API, 1920x1080: 169 fps, 2560x1440: 121 fps, 3840x2160: 71 fps.
    https://ibb.co/WFyJxqG
    https://ibb.co/6RPnW7T
    https://ibb.co/wKQ533N

    Horizon Zero Dawn, 1920x1080: 86 fps, 2560x1440: 69 fps, 3840x2160: 38 fps.
    https://ibb.co/Yd52RGq
    https://ibb.co/syGD6Vk
    https://ibb.co/zFTyVrJ

    All in all, no difference on my PC. I know these are older games, but this is what I play right now, i wish i had time to test more games.
    I also own Cyberpunk 2077 but it doesn't have a built in benchmark, and i don't know how to properly benchmark it, but playing the game the fps was the same, in both situations, around 60 fps with everything on max, except Screen Space reflections which were on "ultra" not "psycho".
    Maybe newer and future games will make a difference even on older platforms like my own.
     
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  18. Astyanax

    Astyanax Ancient Guru

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    the 5700xt won't benefit from it, its already Maxed out.
     
  19. bobblunderton

    bobblunderton Master Guru

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    Thanks to all that have been adding info on this topic. It's been a bit of a foggy realm as of late, and any good useful info is appreciated highly.
     
  20. JonasBeckman

    JonasBeckman Ancient Guru

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    Yeah AMD's lack of what SAM actually is and how that fits in makes things a bit more difficult I would hope it's just their name for the driver utilizing extended address ranges on the GPU and above 256 MB at a time here.
    Forza 4 and Assassin's Creed Valhalla as two known outliers benefiting from this more than others making it easy for comparisons and then with Linux and Vulkan support now landing this opens it up a bit but it's still the 2 - 3% on average gains.

    Pretty sure both drivers Linux and Windows also for now require the 6000 series GPU hardware until AMD extends this if at all possible suppose we'll see.
    NVIDIA and their support for this as well in some future driver would think after the holidays now things are slowly starting up again but I wouldn't know the time frames and multiple driver branches being worked on. :)
    (Windows 10 21H1 support as a large project I would expect for launch around May - April bit earlier for the final build to hit insiders and such but that doesn't usually affect stable release drivers.)

    AMD possibly having their large feature driver for March and what that might bring, RDNA supported super sampled upscaling via Fidelity FX perhaps though I am fairly certain this is still per-game implemented and supported same as DLSS on NVIDIA's list of features would be so support is going to start out pretty slow could also be similar to NVIDIA and DLSS starting out so it'll take some work and a number of revisions for it to really see what it can do.
    (But AMD's taking forever with some of these features and support, workstation state seem to be worse too with RDNA and lack of functionality and AMD's lack of communication is really hindering things too unless you're a bigger customer.)

    Bunch of other stuff too but separate from ReBAR here, will be interesting to see what happens. :)


    It does seem there's potential performance decreases too with this, found a better comparison image too via Tech Spot and not just for 1920x1080 either.
    [​IMG]

    Interesting gains there, still averages out around the 3% mark but a few more games are showing nice gains and also of interest a couple of decreases with Apex Legens and Serious Sam 4 standing out with larger drops in framerate here.
    Wonder how Hitman V.3 will handle it, should be out soon-ish though EGS exclusive at first.

    Ray-traced baldness reflections...
     
    Last edited: Jan 7, 2021

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