Chinese X79 Motherboard BIOS Mod: Unlocking RAM and CPU Multiplier Overclocking

Why this is needed / how it works

Chinese X79 / LGA2011 boards (Huananzhi, Kllisre, Jingsha, Machinist, PlexHD/X79T, and countless rebrands) almost universally run on BIOS firmware built with the American Megatrends (AMI Aptio IV) framework. Manufacturers routinely ship these boards with memory-overclocking and CPU-multiplier-overclocking options artificially disabled in the firmware, even though the underlying reference code from Intel fully supports both. Because nearly all of these boards share the same AMI codebase, the same patching technique works across almost the entire line-up — you’re not hacking around a limitation, you’re simply re-enabling functionality that Intel’s own reference BIOS module already contains but the vendor switched off.

The mod works by locating the specific firmware module (a PE32 executable embedded inside the BIOS image) responsible for a given feature, then flipping a handful of bytes inside it that control a conditional check gating that feature.

Before you start editing, make sure your board’s BIOS genuinely doesn’t respond to changes in memory frequency and CPU multiplier. By now, many manufacturers already ship firmware with these patches applied by default.

CPU overclocking is done from the Advanced → CPU Power Management Configuration menu; the multiplier for each core is set individually in the Core Ratio Limit field (these fields only appear once the CPU is unlocked). Memory overclocking is done from the Chipset → North Bridge menu, in the DDR Speed field.

Before you start

1. Back up your full BIOS image (8 MB) using any method supported by your board — either using software tools (Intel FPT, AFUWIN, AFUDOS) or an external SPI programmer.
2. Confirm your flashing method in advance. Ensure you can both read from and write to your chip using your tool of choice before applying any mods.
3. Download the required software.

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Required software

• UEFITool 0.28.0 — the tool used to browse the BIOS image, locate modules by GUID, and extract/replace their contents.
• AMIBCP 4.55 — used here to check whether your BIOS already exposes a hidden timings menu (see the note in Step 0 below).
• Any hex editor. The original guide uses the free HxD editor, which works fine for this purpose.

You can find all the necessary software in this Telegram channel.

Step 0 — Dumping your current BIOS

Before modifying anything, pull a full dump of the BIOS currently installed on your board and put it somewhere safe. This is your emergency recovery copy — if a flash goes wrong, this is what you reflash to get back to a working state (via an SPI programmer, if the board no longer boots).

Before applying the memory-frequency unlock patch, open your BIOS in AMIBCP and check whether it already has a hidden timings/memory-frequency menu. Go to the Setup Configuration tab, expand Advanced, and check for a Performance Tuning entry containing a North Bridge Configuration menu. If you see a timings menu like the one in the screenshot below, your BIOS doesn’t need the memory patch at all (although applying it won’t cause any harm) — you simply need to unhide that menu by following this guide.

Part 1 — Unlocking RAM overclocking

This mod re-enables manual memory frequency control that the vendor locked out in the BIOS setup menu.

Once you have your safety dump, rename the working copy you’re about to edit to something memorable, e.g. mod.rom (or .bin, matching the extension your dump tool produced), and open it in UEFITool.

1. With your dump open in UEFITool, press Ctrl+F to open the search dialog. Switch to the GUID tab and search for:

   5C08C7C8-24C2-4400-9627-CF2869421E06

   

2. Click OK — UEFITool will report a successful match. Double-click the result at the bottom of the window, then expand the tree that appears. You’re looking for the PE32 image located inside the IvtQpiAndMrcInit module.
   

   

3. Right-click that PE32 image entry and choose Extract body. Save it with an easily recognizable name, e.g. ram.
   

   

4. Open the extracted ram file in your hex editor.
   

   

5. Press Ctrl+F, switch to the HEX-values search mode, and search for:

   3B D1 7E 06

   

6. Replace the found bytes with:

   3B D1 7E 00

   Save the file.

   

7. Back in UEFITool, right-click the same PE32 image entry and choose Replace body, then select your edited ram file.
   

   

8. Check the Action column — after this step it should now show Rebuild and Rebase next to the modified entry. That confirms UEFITool registered the change correctly. The RAM overclocking patch is now applied.
   

   

Part 2 — Unlocking CPU overclocking (multiplier)

This mod re-enables the “Core Ratio Limit” (multiplier) control for CPUs that support it: the Xeon E5-1600 family (except the Xeon E5-1620 v2) and the Core-i7 family.

1. Still in UEFITool, press Ctrl+F again, switch to the GUID tab and search for:

   8C783970-F02A-4A4D-AF09-8797A51EEC8D

   

2. Click OK. Double-click the match at the bottom, then expand the tree. This time you need the PE32 image located inside the PowerManagement module.
   

   

3. Right-click it and choose Extract body. Save it with a clear name, such as cpu.
   

   

4. Open the saved cpu file in your hex editor.
   

   

5. Press Ctrl+F, switch to HEX-values, and search for:

   40 02 F8

   

6. Replace it with:

   40 B7 7F

   Save the file.

   

7. Back in UEFITool, right-click the module entry and select Replace body, then choose your patched cpu file.
   

   

8. Confirm that Rebase and Rebuild now appear in the Action column for this entry.
   

   

9. Save the resulting image: File → Save image File. The modification is complete — you now have a modified BIOS dump ready to flash. Don’t forget you still have your original, unmodified backup saved separately.

That’s it. All that remains is to flash your mod BIOS using any method suitable for your board.

Post‑flash checks

1. Power off completely, clear CMOS (jumper or battery), then power on and enter BIOS.
2. Load Optimized Defaults, Save & Exit, then re‑enter the BIOS.
3. Navigate to Advanced → CPU Power Management Configuration and enter the multiplier values for each core. Don’t set maximum values right away — a value around 40 is a reasonably safe starting point to confirm the unlock is working before pushing higher frequencies.
4. Navigate to Chipset → North Bridge and enter your desired memory frequency in the DDR Speed field.
5. Save the BIOS settings, boot into the OS, and check if your new values were actually applied using tools like CPU-Z or AIDA64. Once verified, run a stability test to ensure your system is completely stable.

Tips, pitfalls and troubleshooting

• Always keep the original dump. Before applying any patch, save an untouched copy of the BIOS you pulled in Step 0, separate from the file you’re editing. It’s your only way to restore the board via software if something goes wrong.
• If you can’t find the required values in the hex editor: make sure you’re searching in HEX-values mode specifically. If the original values still can’t be found, search for the replacement (already-patched) values instead — if those turn up, your BIOS already has these patches applied.
• If the board won’t boot after flashing (no POST, powers off after a couple of seconds), first try clearing CMOS with the jumper/battery-pull method described above. If that doesn’t help, recovery will require an external SPI programmer.

Source material and screenshots: e5450.com.