New member
Dec 7, 2017
I am sharing my modded bios! So....

Bought an X399 SLI Plus and noticed that there were some missing ... features.

After some research here and there I saw that the AMD CBS menu is in there but hidden/disabled, so... well, I had to enable it and it "sorta" works: all options should work flawlessly, apart one: it looks like Custom PState management is somewhat broken.
Whenever you try to set a custom VID for a PState, the motherboard will sometimes not boot (freeze on diag code 68) and sometimes not set the VID... I did that because I wanted to lower the lowest pstate to 1.6GHz and lower voltages to save power...

1. I tried to raise the voltage for PState 0 because I wanted to overclock: this resulted in freeze on diag code 68
2. Tried to lower the voltage for PState 2 because I wanted to save power: this resulted in either VID change IGNORED or freeze on diag code 68
3. Tried to activate PStates that are undeclared from the processor... and this resulted in complete breakage (both Windows and Linux 4.15-rc2 crashed at boot), but that's okay, I expected that to happen.

Whenever the motherboard goes nuts and freezes on code 68, all it takes to bring it back is to press the CMOS Clear button and watch it reboot.

Another issue: when you try to set Custom PStates, you will be tempted to either use the +/- keys or write HEX... if you use the +/- keys, it will WRITE + or - on the value :-)censored:?), but if you try to enter an HEX value with a letter, that won't work. Explaining better, +/- writes +/-, keys from A to F will not write anything. Odd. Odd. Odd... and disappointing!

Well, since basically everything is working (apart what I needed..) being selfish would be poor, hence I am sharing my modded file.

Another thing, if anyone from MSI is reading this... well, first of all, this is not my first MSI motherboard. I LOVE THEM.
If you can help fixing the Custom PStates bug.. PLEASE.... I'd love you even more, MSI.

Enough talking now.
Here's the link: https://drive.google.com/file/d/1XHG2fI2NbXMdKD0Sd1g1Syzgo8_DBo4Q/view?usp=sharing

P.S.: Based on 7B09vA1

Enjoy, folks!


New member
Dec 7, 2017
New updates!
I've successfully modded the new 7B09A2 BIOS, but this time with more efforts and less bugs! Now Custom PStates can be finally properly set with your keyboard +/- keys.

Since I've been able to solve that bug, I got curious again on what could I do with it and:
1. PState 0 voltage+clock raise results in successful boot! YAY!
2. Other PStates clock modifications will result in freeze on diag code 68
3. Other PStates VID modifications will not be ignored... partially: reading the CPU VID on the fly (from the OS) will show the lower VID, but then the motherboard will ignore that and set the stock voltage (example: stock is 0.85V, modified VID is 0.75V - requested VID will be 0.75, motherboard will set 0.85V anyway)
4. Adding/enabling more PStates (compared to the number of PStates already declared by stock configuration) results in completely non functional CPU scaling (so it's completely useless)

Also, overvolting the PState0 will strangely trigger a similar bug, as described in point 3: CPU frequency scaling will work, but voltage scaling will not!
... and even more strange, the CPU VID table is getting sorta screwed as well.... and... of course, the motherboard will fix the voltage for all PStates to the one of PState0.

This is seriously poor: other X399 motherboards (from other vendors) aren't showing this poor behavior, so it's not like it being a chipset issue or some hardware limitation... that's just poorly written software (in this case, our BIOS). That's deluding, completely.

So..... in conclusion, that's the new stuff:
- Based on 7B09A2
- AMD PBS enabled
- AMD CBS enabled
- +/- keys bug on CBS Custom PStates FIXED

Download here: https://drive.google.com/open?id=1ICn02S1meA9A2hGuj0pWeqGjgdyD0L-m


New member
Apr 1, 2020
Hi kholk11,

do you have latest bios for this board modded? Im kind a missing these disabled features :-).