[Offer] GA-B75M-D3H with NVMe + Resiz./Large BAR Support

Based on official F16d NVMe beta BIOS by Gigabyte.

Here is the list of modifications

  • ReBarUEFI DXE driver added for Resizable BAR support.
  • PciHostBridge patched to remove <4GB BAR size limit.
  • PciBus patched to remove <16GB BAR size limit. Should now be capable of 16GB BAR (or 8GB with 32GB of RAM).
  • PciHostBridge patched to increase BAR allocation region from 16GB to the full physical address range (64GB - (RAM+1GB)).
  • DSDT modification to allow full use of the physical address range (required for above)
  • Fixes for UEFI PciIo protocol
  • Fix USB 3 ports in BIOS with 4G decoding turned on
  • Above patches were taken from ReBarUEFI repo and applied with UEFIPatch

image

How to enable Resizable BAR

Make sure CSM is disabled (OS type set to Windows 8 WHQL in setup should let you).

Use grub-mod-setup_var to do setup_var 0x3 0x0, reboot, do setup_var 0x3 0x1 and then again reboot. This should get 4G decoding enabled.

With the new release you can find 4G decoding under the blank menu in System tab in BIOS, enable it.

Download ReBarState and use it to set the BAR to the size of your VRAM or unlimited and reboot. Windows will tell you to reboot again and it should be working if your GPU and driver supports it.

B75MD3HGC NVMe+ReBar.zip (4.4 MB)

Flash using Q-Flash in BIOS setup


Edit by Fernando: Thread title shortened (w/o missing any important info)

3 Likes

Hi,

I did everything but on AMD Adrenaline, it says Resizeable BAR not available. GPU-Z says it’s enabled, and it says the BAR size is 8192MB. I have the same GPU as you btw. I’m also on the latest drivers and tried reinstalling them but still says not available. Do you know how I can fix this? Thanks.

@MD2
REBAR_Legacy_On_-_Experimental.zip (361 Bytes)

apply the reg file in the zip and reboot. it enables rebar for GPUs before 5000 series like rx 580.

It worked, I can see Resizeable BAR now enabled in Adrenaline. Thank you so much!

@Kuri0
Can you please upload this same bios mod but for revision 1.1 of this motherboard
“GA-B75M-D3H (rev. 1.1)”? Thanks!

@BobbyBadBoy actually i have the rev 1.1 of this board. you should be able to use it on all revisions btw

1 Like

I am having trouble figuring out which chip it has, can you please tell me the brand and model of the chip so that i can input the settings into the BIOS chip Flashing tool (ezp 2019 program)? thanks!

my motherboard was bricked so i needed to remove the chip completely, but I dont have good enough magnificaiton to see what the IC says on top

did dual bios restore not work ? i’m not sure if you can flash this image directly as it won’t contain MAC address, serial number etc. i think others on this forum know better about using flasher than me i’ve never done it.

the numbers on ICs are engraved so any sort of white powder will make them more visible.

nope, the dual bios is exactly what screwed the whole thing, it seems like a pervasive issue with Gigabyte boards, turns out this dual “durability” bios BS just causes more problems than anything else. I swapped out the RAM and then it just started trying to restore a bios or something and then ended up in an infinite boot loop.

I have seen a video of a guy just fixing one of the bios chips then removing the second one to avoid these backup issues.

I was able to flash both now, it is a “winbond 25Q64” (or something like that). using the clip wont work I had to remove both completely. I am probably only gonna install the main one and leave the backup one off.

I already flashed it directly on the bare chip so if it lost the mac address and serial number or whatever, I might be screwed. However it was bricked and I dont think I would have been able to extract that information anyway.

The main chip was unreadable. however the second chip was readable, but I already overwrote it lol… so any chance of me being able to restore the mac address was lost however it may not be a big deal. IDK about this 'serial number" thingy though. I will just try to boot it and I will Let you know if it worked.

I flashed the chips and resoldered them, first the mobo was not even spinning the fans. then I removed the second chip and just left one of them on and I am back to square-one, because when I boot up, the fans spin briefly then stop, and then they spin again and stop, and its practically stuck in an infinite loop of spinning the fans up and off.

I am not too worried about this board, I am not gonna be missing it. I think I am done with Gigabyte stuff forever.

I will just try one more time and then just trash this thing. I will flash a stock BIOS just to see if I can revive it. and if not I will just throw it out.

Hi, sorry to bother you I have another question.

Would it be possible to enable OC settings through Grub?

this motherboard can’t OC CPU besides using BCLK (which is kinda risky and can result in data loss). It technically should be able to OC RAM though but I haven’t figured that out.

I see. I think in older BIOS versions it was possible to OC the RAM but however they took away this option in later updates for some reason. I think it was possible in F.5 as I recall. I tried using AMIBCP to see if anything was available to change and I couldn’t find anything. Unless I missed anything out. Anyway I have this board paired with a i5-2500k, no point upgrading anything.

@MD2 Resizable BAR works for you with the 2500k ? I thought it would require PCIe Gen3 which 2500k doesn’t have.

Can you send a screenshot of GPU-Z main page ?

I’m confused because in the footnotes of older BIOS updates, I think it was F5 it said “enhanced overclocking capability” maybe it’s referring to the RAM. Do you know how to change the BCLK? I want to get some extra juice out of this i5, I think it’s slightly bottlenecking certain games and right now I don’t think I can upgrade.

@MD2 it’s in M.I.T Advanced Frequency Settings in the BIOS or something. most I could do was 104.7mhz before AHCI stopped working, at 105.5mhz NVMe stopped working.

also you could send a screenshot of GPU-Z showing the main page with AMD control panel open next to it showing resizable BAR enabled that would helpful

Mine doesn’t let me increase the CPU clock ratio beyond 34. I don’t see any BCLK options either.

@MD2