[Request] Asus Z97-K R2.0 Resizable BAR - advice before flashing (i7-5775C + RX 9060 XT)

BIOS/UEFI Modding BIOS Modding Requests
1

Hi all,

I want to add Resizable BAR to my Asus Z97-K R2.0 and I’d like some advice before I flash anything.

My setup:

  • Board: Board: Asus Z97-K R2.0, BIOS version 0903 (02/26/2016)
  • CPU: i7-5775C (Broadwell)
  • GPU: RX 9060 XT 16GB
  • RAM: 24GB
  • OS: Windows 10 Enterprise LTSC (19044), UEFI/GPT install, Secure Boot on

Why I want this: guides for the RX 9060 XT (for example https://www.youtube.com/watch?v=2BcuUj6HcB0) say Resizable BAR + Above 4G Decoding are needed for the card to perform as expected, and AMD Adrenalin shows Resizable BAR as unavailable on my system. I know those guides assume a modern board with native support, so I’d like to know if it is realistic to expect a gain on Z97.

What I have read so far:

  • The Z97-K (non R2.0) request thread by @Matrix and the Tesla P40 guide by @wa5her.
  • The Z97-A offer thread by @Koekieezz. I extracted that ROM and it has the full set applied: PciBus (16GB limit, no 64->32 downgrade, 9-series USB3 blacklist), PciHostBridge (4GB limit + 512GB MMIO), NBPEI 39-bit, NvramSmi unlock, plus ReBarDxe 0.3 and NvStrapsReBar.

My plan is the same recipe on the official R2.0 BIOS: insert ReBarDxe with MMTool 5.02.0024 Mod, run UEFIPatch with patches.txt + BdwUSB3.txt, then replace PciBus, PciHostBridge and NvramSmi with MMTool. No DSDT patching.

My questions:

  1. Is the R2.0 BIOS different from the Z97-K in any way that matters for this mod, or does the same recipe apply?

  2. @Matrix measured lower fps in games with the patched BIOS on a 4790K + RX 6700 XT, even with ReBarState set to 0. Has anyone else benchmarked ReBAR on an Asus Z97 board? Does anyone know the cause?

  3. Could the 512GB MMIO + NBPEI 39-bit patches be the reason (GPU BAR allocated at a very high address)? With 24GB RAM and a 16GB BAR, would it be safe to skip those two patches and let the BAR sit in the stock 32-63GB region?

  4. Anything specific to Broadwell (5775C) I should watch for?

  5. I don’t own a CH341A yet and I plan to buy one before flashing. Is the BIOS chip socketed on the R2.0 like on the Z97-K? Is there any safe flashing method on this board without a programmer?

I will post benchmarks (ReBAR on/off, stock vs modded BIOS) once it’s working, so there is some data for this platform.

Thanks in advance.

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A post was merged into an existing topic: [Release] Resizable BAR BIOS EFI Module