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  • Sanity Test wanted on BIOS editing to enable BAR support.

    From Andrew Singleton@singletona082@ctrl-c.club to tilde.projects on Fri Mar 28 10:36:55 2025
    tl;dr: Trying to enable BAR on my Haswell Architecture desktop.

    This is going to take a lot of text, apologies, but I both knowthat
    this task is very unforgiving of mistakes, and i understand just enough
    to know that I could turn the computer I've had for... a decade, into a paperweight if I mess up.

    My computer: https://support.lenovo.com/us/en/solutions/pd029601-detailed-specifications-for-thinkcentre-m73-small-form-factor

    My Motherboard:
    https://ctrl-c.club/~singletona082/lenovo-m73sff-mobo.txt

    The last bios Lenovo published for this computer: https://support.lenovo.com/us/en/downloads/ds038324-flash-bios-update-thinkcentre-m73-tower-and-small-form-factor-thinkcentre-e73


    What I want to do:
    Add BAR support to a computer that doesn't have it

    'What is BAR?'
    https://www.howtogeek.com/819578/what-is-resizable-bar-on-a-gpu/

    I am planning on using this guide: https://github.com/xCuri0/ReBarUEFI?tab=readme-ov-file

    Right now I'm looking at the following: https://github.com/xCuri0/ReBarUEFI/wiki/Enabling-hidden-4G-decoding
    Notes:
    At step 6: there were no results for '4g decor', but there were for
    'Above 4G'. If I'm reading this right what I'm looking for is
    'VarOffset' and if I have the right of what I'm looking for mine is a
    value of '0x2CE'

    I have not progressed past this step since it involves making changes
    to UEFI.

    The above is listed as an optional, but nice to have, step since
    otherwise BAR allocation is capped at 1G or 512mb.

    What I want from the peanut gallary here, especially xwindows if he's
    feeling helpful or at least curious on how things explode, is if any of
    this is even worth doing outside of a technical level 'huh neat' and
    any advice or color commentary about the instructions listed.

    --- Synchronet 3.20a-Linux NewsLink 1.2
  • From Andrew Singleton@singletona082@ctrl-c.club to tilde.projects on Fri Mar 28 16:45:07 2025
    Update:
    UEFI change has resulted in no explosions. I have made preparations to
    the bios file as per instructions.

    However reading further suggests that past enabling 4G via the
    bootloader will do the job and a bios reflash is needed only if one is
    using Windows. Given Windows 10 support stops this year for non
    corporate users ( so much for, 'last version of windows...') and this
    computer not meeting the TPM requirements for windows 11? If what i
    have done is enough, then I see no reason to go further.

    It's still a severe bottleneck even if I upgrade on the cheap to the
    fastest xeon that would fit in, and get a nicer card, but this box is
    mine and my wants, such as they are, are few enough that just making
    things that little bit nicer is enough, until some other tweak presents
    itself.

    --- Synchronet 3.20a-Linux NewsLink 1.2
  • From Caden Kray@ck1998@yahoo.com to tilde.projects on Sat Mar 29 20:47:43 2025
    Andrew Singleton <singletona082@ctrl-c.club> writes:

    tl;dr: Trying to enable BAR on my Haswell Architecture desktop.

    I know nothing about the subject, but I appreciated your attention in
    providing references such as what is BAR. I wish you good luck on the operation and will watch your progress here, trying to understand how
    stuff works.
    --- Synchronet 3.20a-Linux NewsLink 1.2
  • From Andrew Singleton@singletona082@ctrl-c.club to tilde.projects on Wed Apr 9 11:45:01 2025
    Update:
    While gains on my system seem (relatively) small (in large part due to
    my computer's age, bottlenecks from older PCI-E spec, CPU
    bottle-necking, alongside a (by modern standards) lower capability GPU
    (RX550, i THINK 4gb, could be the 2gb variant,) gains. They are
    noticeable just from the initial 'enable 4G block support' step

    https://github.com/xCuri0/ReBarUEFI/wiki/Enabling-hidden-4G-decoding

    if I am reading the rest correctly, with that enabled the linux kernel
    and AMD drivers should handle the rest. As the next steps do not seem
    to be needed I am tabling them for the moment while I look into other
    potential modifications (and fretting the whole time I'm going to
    destroy my computer in the process.)


    --- Synchronet 3.20a-Linux NewsLink 1.2