Hello Win-Raid community,
My native language is not English, so this post was translated and polished with the help of ChatGPT. Please excuse any awkward phrasing.
I’m posting to share my current findings and to ask for help from experienced BIOS modders who might be willing to take this further. The practical problem is the VDDIO hard cap on Gigabyte X870E boards (especially the newer X3D models). On my X870E AORUS PRO X3D, VDDIO is capped at 1.45V in BIOS, which limits DDR5 overclocking headroom.
This topic was already discussed in this community earlier this year in the context of the X870E AORUS AI TOP, which uses a 32MB BIOS image. From that discussion, I understand the community managed to relax/unlock VDD and VDDQ, but could not bypass the VDDIO limitation. That result is exactly why I’m trying to bring new comparison material and a clearer lead.
In August, a leaked Gigabyte XOC/test BIOS “T86” for the X870 AORUS TACHYON ICE appeared, and it is reported to relax voltage limits compared to regular releases. For my “limited” baseline, I used the official F4 BIOS (updated in July). When I compared official F4 against leaked T86, I found a very small and clean delta inside AodDxe:
AodDxe FFS GUID: 442ba91e-b0a8-499f-94f7-2e922c9aae0d
Inside this FFS, the PE32 differs by exactly 14 bytes, which corresponds to 7 changes of 16-bit constants.
Two changes are:
0x05D0 → 0x0620
0x05C8 → 0x0618
Five other changes are:
1650 → 2070 (repeated five times)
I do not claim to fully understand what each constant controls yet. I’m sharing this because it is an unusually “clean” diff between a constrained official BIOS and an XOC BIOS that reportedly relaxes limits, so it feels like one of the best leads we have.
Where I’m stuck is not the willingness to test, but the tooling situation with the newer 64MB BIOS format. On my target board (X870E AORUS PRO X3D), UEFITool 0.28 behaves poorly with these newer 64MB Gigabyte BIOS images. UEFITool NE can browse and extract modules reliably, but it cannot rebuild/write a modified image. I tried many approaches and still failed to produce a valid, flashable 64MB modded BIOS.
At this point, I’m essentially handing over my work to the community: I can provide everything that might be useful for someone to continue, including all relevant BIOS files (official F4, leaked T86, and my board’s BIOS if needed), the extracted AodDxe module/sections, the exact diff details, the tools and steps I used, and also a PE32 that I already patched to match the 14-byte / 7-constant changes so that anyone taking over can focus on analysis and a proper rebuild workflow instead of repeating the same preparation work.
If someone can take this over and also propose a practical solution/toolchain for modifying and rebuilding these new 64MB BIOS images, it would help not only this VDDIO cap issue but also future work, because larger BIOS images seem to be the direction vendors are moving toward.
Thank you for your time, and thanks in advance to anyone who can help push this forward.
Edit by Fernando: Thread title shortened and customized