Resizeable BAR support issues

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

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  1. Wault

    Wault Member

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    For what it's worth, I used the method in this documentation and I can say it worked. :)

    I took my time, though, to fully read and understand the commands, and to save my data beforehand, just in case.

    If I recall, I used a 8GBytes USB-key with a Windows 10 install on it (https://www.microsoft.com/fr-fr/d/w...f77x4d43rkt?rtc=1&activetab=pivot:overviewtab).
     
    Netherwind likes this.
  2. Espionage724

    Espionage724 Member Guru

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    With Windows "11" 21966 and UWP V30 driver, AMD's UWP control panel now reports SAM status. It shows as Not Available for me though, but I'm not certain if it's actually not available (hardware/driver), or if the setting just isn't implemented to read the status yet. If anyone has a GPU and configuration that has advertised support for SAM, I wonder if the SAM option reports anything?

    [​IMG]
     
  3. LocoDiceGR

    LocoDiceGR Ancient Guru

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  4. Undying

    Undying Ancient Guru

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    And your gpu does not support sam.
     

  5. Espionage724

    Espionage724 Member Guru

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    I'm well aware of this. The SAM option also appears on the branch 30 drivers even when installed on 19041 (stable W10), so this doesn't seem specific to 21996.

    I'd like to see a report from anyone with a GPU that's "officially" supported by AMD to advertise SAM support. If the option shows something different than Not Available, then it'll appear the option does something.

    For anyone interested in testing this, you need the latest UWP driver (30.0.13000.17006 currently), and check under Performance -> Tuning. The latest UWP driver works fine on 19041 W10.
     
  6. Espionage724

    Espionage724 Member Guru

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    With the latest official AMD driver (21.6.1), along with the V30 branch UWP drivers, SAM status is reported. This is the case with both stable W10 (19043) and W11 builds currently (leaked 21996 and the official 22000 insider preview released today).

    There's inconsistencies as to how Resizable BAR and/or SAM are reported, but it's possible it's a misunderstanding on my part. What are the clear and detailed differences (if any) between Resizeable BAR and AMD Smart Access Memory/SAM?

    In my case (RX 580), Radeon control panel says its still using 256MB of memory and SAM is not available, and shows the Smart Tool (cloud) as grayed-out (I have a 2700X and RX 580, two AMD devices). GPU-Z and Windows Device Manager both report the increased memory range after enabling Resizable BAR.

    I'm not convinced this is just a simple "unsupported GPU" ordeal, or that there's more to it than that. I'm leaning towards Radeon control panel not reporting the information correctly since:
    • GPU-Z and Device Manager show changes in the memory range when toggling the Resizable BAR option
    • Older unsupported AMD device drivers break VRAM reporting when toggling the Resizble BAR option, proving that the option does something in-relation to the driver
    • Linux reports clear BAR memory sizing adjustments when toggling the Resizable BAR option
    • HWInfo reports Resizable BAR being enabled and supported
    Images:

    Specs:
    • RX 580 (21.6.1)
    • 2700X
    • ASUS PRIME X470-PRO (latest 5851 bios)
    • Windows 10 (19043)
    • Firmware settings: CSM off, W10 UEFI, above 4G decode enabled, Resizeable BAR enabled
    • Above is all also true on W11 (22000), 30.0.13000.17006 driver, and 10.21.30011.0 Radeon control panel
     
    Last edited: Jul 21, 2021
  7. Scoty

    Scoty Active Member

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    I have exact the same issues with my drives. Whene i enabled rBAR in the Bios and i install GPU Driver this kicked my drives out, also USB and LAN. Installations hang on 99% for 1 minutes and whene finish my drives, usb and lan is working again. I dont have this issues wehen rBAR is disables in the Bios. But whene i enabled again the issues is back.
     
  8. Netherwind

    Netherwind Ancient Guru

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    Apparently the solution is to either convert the drive to GPT using a tool or reinstall Windows in GPT mode. I'm too lazy to do either of these solutions as the converter could potentially damage files and I don't like reinstalling everything.
     
  9. Scoty

    Scoty Active Member

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    I use UEFI and gpt.
     
  10. Al3XKOoL

    Al3XKOoL New Member

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    GPU:
    RX 5500 XT 8GB MECH
    Hi!

    My gpu is RX 5500 XT not supported by AMD SAM.
    For me SAM is now working after some changes.


    BIOS:
    CMS= Disabled
    4G Above= Enabled
    Resizable Bar= Enabled

    Install Win 11.
    Install "AMD Radeon Software - UWP - v30.0.13000.17006"
    Install Radeon control panel from Windows Store.

    All done.
    [​IMG]

    GPU-Z show unsupported gpu after enabling it on radeon software.
    [​IMG]
     
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  11. Undying

    Undying Ancient Guru

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    how can it work when its clearly say unsupported gpu? Only thing you did is enabled in bios that does not mean it works.
     
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  12. Al3XKOoL

    Al3XKOoL New Member

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    GPU:
    RX 5500 XT 8GB MECH
    If you see radeon software screenshot, sam is enabled.
    Also check for large memory.

    When i get some free time i will try some games enabled/disabled.
     
  13. RaulR

    RaulR Master Guru

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    Hello, I have a Ryzen 2700x, MSI X470 Mb, and a RX 5700 XT, I already did some tests a couple of months ago, with Resize Bar enabled/disabled:
    https://forums.guru3d.com/threads/resizeable-bar-support-issues.435389/page-3#post-5874736
    I found there was no difference in performance in both cases, so even if it can be enabled in UEFI, and GPU-Z says it's enabled, it doesn't mean that it's working. Also the AMD driver reports SAM status as beeing "not available". As i understand only CPU's starting with Ryzen 3000/ Zen 2 support this feature in hardware.
    Anyway since then I just left it enabled and moved on. In my opinion if you want a real, "tangible" solution, just enable Radeon Anti-Lag in the driver settings, it works wonders for me!
     
  14. Al3XKOoL

    Al3XKOoL New Member

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    GPU:
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    Your CPU us not supported.
    Already tested anti-lag, it work very well.

    I already post a screenshot with SAM enabled in the AMD Radeon control panel.

    This is not enabled: Screenshot_20210719-090921283~2.jpg


    This is my panel (sorry, is in spanish) with sam enabled:
    Screenshot_20210719-090943699~2.jpg
     

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