Attempting to overclock a Precision M6800 & Failing (Collection of all my "research" and attempts)

[BYTEHAT248]

After countless hours of attempting to unlock the advanced menus in the precision M6800s, ive had no luck, even with posting asking about it on bios-mods.com, but I have learned quite a few things about modding the bios that may help others in doing what I was not able to or maybe someone could help me do it. so i compiled everything i found online (+ stuff i did on my own) about this to post it all here.

(My Precisions specs, ME Disabled, BIOS Ver A16, CPU: i7 4930MX, GPU: FirePro M6100, 12GB RAM, Fedora)

 

Before any thing else I should note that if your are going to attempt any of the things here, know that there is a chance you could brick your motherboard and the only way to fix it would be a external programmer.

 

Part 1: Modifying setup variables with setup_var in a grub prompt (if somebody wants what commands i ran to change the MSR values on linux let me know)
So when i got this machine i picked it specifically as a project computer, to try to push it to its absolute limits in terms of performance. So first i started researching gpu upgrades, i ended up finding that the GTX 1070 MXM is the best choice for me but it only works on linux. And then i started looking for ways online to overclock the CPU, and found, mostly nothing. Other than a post on a no longer existing forum.( https://www.nbrchive.net/forum.notebookreview.com/threads/guide-dell-precision-m6800-m4800-sbios-mod.788481/index.html ). The user (valuxin) that made that guide is also the person that made the Mystery Magic VBIOS for the FirePro M6100 (i currently have it on my card). So i thought why not try it. Well I changed all the variables to unlocked, and well i was able to change MSR values with the wrmsr command on linux, and while it did change the values, my cpu (i changed the values to turn off all power limits on the CPU and raise its max Turbo freq to 4.2ghz all cores), the only thing that it actually did was allow it to boost to 3.9ghz and hold it. according to turbostat it was not boosting past 3900mhz at all. So it was time to try something else

 

 

Part 2: Manually changing hex values with RU.efi
So i realized pretty fast it wasnt going to be as easy as i thought it was to overclock this thing, so i did some research and figured out that i could just manually write hex values with RU.efi, so i dumped my bios and opened it up in UEFITool and then extracted the setup PE32 Image, then i extracted the IFR tables. And then spent a while figuring out what was what until i figured out what needed to be changed 

 

The offsets needed to be changed were in var store 0x15 (Setup) they were: 0x23 (to 0A), 0x24 (to 2A), 0x25 (to 2A), 0x26 (to 29), 0x27 (to 29), 0x2F (to FF), 0x30 (to FF), 0x31 (to FF), 0x4C (to FF) .

I then saved and rebooted and Turbostat (and corefreq) was now saying that my CPU was set to boost up to 4.2ghz on 2 cores and 4.1ghz on 4 cores. But it still wasnt boosting past 3.9ghz.

(there was one other thing too, in RU there was a  var store called SystemAccess, in it was a single offset, 1 byte, it was set to 0x00, now i thought to myself, theres no way that wont do at least something, so i set it to 0x01, nothing. but when i went back to RU.efi it was set back to 0x00, i tried to set it to 0x01 again, i reboot and then go back into ru and its right back to 0x00, it was reseting itself, and since i didnt know what exactly it did, i just left it alone forgot about it)

So I thought that maybe i was going about it all wrong, maybe i just needed to figure out a way to unhide the advanced menu, or put one in.

 

 

Part 3: Attempting to unlock the advanced menu in the bios (and failing due to not knowing enough about bios modding)
So at this point i had kinda given up, i was only looking online and hoping to find some kind of guide or premade bios, and i did end up finding something (https://forums.mydigitallife.net/threads/tutorial-ami-aptio-uefi-advanced-menu-unlock-bonus-msr-unlock.54523/) a guide on how to unlock the advanced menus in the bios of the Precision M3800. Now the precision m6800 and m3800 are 2 very different computers, but they probably  both use the same base for there bioses since they are both M "800" series (yes i know they all use AMI bioses, but i mean a more configured base and considering i found references to DDR2 while looking super deep in my bios dump, a lot of dells computers probably do) so i decided why not try it on my pc, well i looked into the extraced setup IFR tables, and there was only one thing in the forum sets (and in the guide there was multiple things) Main (0x7). I even extracted the bios from the A26 bios setup, and it was the same thing. I had hit a brick and given up, but im hoping someone might be able to succeed where i had not.

 

 

In case they can be of use:

Full A16 BIOS Dump: https://drive.google.com/file/d/1lvxeWrr5YXE1Ik9rTQI8fZeElxgOpJUk/view?usp=sharing
Extracted IFR tables from setup: https://drive.google.com/file/d/1kocG4yWR4Gl5b8_eETgeSzZ8zU6Okqsj/view?usp=sharing
Full Extracted A26 BIOS: https://drive.google.com/file/d/13rtPeStXgEOflKnMWPqZy2vlLcFlKYPN/view?usp=sharing