@ket Driver will check certification in DSDT and PCH , when they matching , the SLI option showing.
And I have tried flash Z370’s BIOS to Z270 ,without replacing the certification in DSDT , SLI won’t work, but replace SLI certification , SLI work.
Anyone know where a windows version of the tool shown in this thread is, or any windows DSDT editor? - [GUIDE] How to make your Mainboard SLI compatible without a BIOS mod
DSDTEditor-Linux-Mac-Win does not open any tool like the guide seems to imply, at least not the package I found here - https://www.techinferno.com/index.php?/f…igpu-dgpu-egpu/
First link above, in guide, the software seems to be this same tool as shown here, but I can’t download it there (some error, try again later) - https://imac.hk/dsdt-editor-for-windows-…dsdt-tools.html
@DarkPoe @chinobino @dsanke
* Edit, got it working in XP, but can’t get it to properly open the extracted body of DSDT GUID for SLI board BIOS so I can start looking around. It opens, but will not populate tree, so all waste of my time it looks like.
So, I don’t think I can help here 
I used RWEverything to get the DSDT table I posted before, but I didn’t get to get the tool working to edit it and I don’t know even how to edit it or what to do with it… 
@DarkPoe - To do it that way, I’d need same table from SLI board. I don’t see your DSDT table from RWE, what post #?
I just noticed, dsanke posted a mod BIOS for you at post #13, did you test it? Thank you dsanke!!
You will need to use driver chinobino linked at post #14 after you flash in the BIOS
@lost_n_bios I thought I uploaded the file though… Sorry about that
And no, I haven’t tried the BIOS, can I modify it with UBU to update everything to the latest and still keep the SLI cert?
DSDT.rar (39 KB)
@DarkPoe - Thanks for that exported table, it’s nearly exact same was what I extracted from the stock BIOS too, so being so similar it also does not open properly in the DSDTEditor
“Pairs of Brackets do not match - Tree Not Updated” is the error I get with either direct body extract or your RWE dump
Test the BIOS as it is, before you do anything with UBU - This way you know the BIOS is OK and generally bootable, before you do anything to it. I would also test the SLI stuff before further edits as well, since that is your concern here.
Never mind, DO NOT Test yet, that BIOS looks BAD! 
And it’s a BIOS region only, so you should not flash it until properly rebuilt into a normal BIOS image.
@dsanke - what happened there?? TONS of errors in UEFITool parser vs stock BIOS? Are you sure that should maybe be bootable???
I would expect not, seeing all that, but maybe it’s OK if you expect to see all those errors different than stock? Also is broken when looking at with AMIBCP, so this is definitely bad BIOS (Aside from being BIOS region only, and volumes are all moved around etc)
What happened, what did you edit it with? Why does it look so unexpectedly different and error filled? Main DXE volume is trashed too, so I can’t even expand it.
The GUID with DSDT table is missing from this search now too, due to the volume being unable to decompress properly - C118F50D-391D-45F4-B3D3-11BC931AA56D - I thought maybe to extract your edit there and put into proper BIOS file, but it’s missing so can’t even do that 
Can you please send me the edited DSDT body only, thanks 
@dsanke - Thank you, that one looks much better 
Don’t worry, I know more than anyone, mistakes can happen when we least expect them
@DarkPoe - New BIOS at post #13 looks OK, please test as is and check for SLI functionality before you further edit.
Flash with Qflash, Clear CMOS after, then enter BIOS and load optimized and save/reboot back to BIOS to make other changes you need, then boot to windows and check it out.
I’ve got it working LOL
It was a little pain in the ass, but I’ve got it working…
So I flashed @dsanke BIOS in #13 post and saw that it contained the SLI certificate with AIDA64, then I updated and made my mods with UBU to the BIOS and flashed it again and still SLI certificate. Now, I went and tried to install and try SLI and it didn’t work, but then I found this utility https://gitlab.com/DonnerPartyOf1/freesli that patches your nVIDIA kernel to enable SLI, but since it messes the signature, I had to use this https://github.com/Mattiwatti/EfiGuard to boot and be able to disable DSE, which now worked and I just used CRU https://www.monitortests.com/forum/Threa…ion-Utility-CRU to restart the driver after disabling DSE and then it worked and it let me enable SLI which is great, although as @chinobino said, bottom slot works at x4 which I tested through GPU-Z render test, but something is something
I don’t know what did it and if there is the need for the SLI certificate BIOS or not, but I have now SLI working even though it is a pain in the ass to get it working each boot
@DarkPoe - Awesome to hear it, thanks to @dsanke and @chinobino !!!
Remember, I said you need to use those modified drivers chinobino linked at post #14 - Maybe less hassles that way, or not sure, maybe similar/same stuff you did too
What made it possible is the SLI certified BIOS dsanke made you
You’re welcome, but my part was minimal
Maybe chinobino knows a way you can run that without having to jump through hoops at each startup?
@DarkPoe @Lost_N_BIOS
Glad you got it to work - it’s a pity that it’s a x4 PCIe slot and you have to use a modified driver.
When I was using SLI on a crossfire motherboard I had to disable driver signature enforcement and disable secure boot policy;
bcdedit /set loadoptions DISABLE_INTEGRITY_CHECKS
bcdedit /set TESTSIGNING ON
and to undo the changes;
bcdedit /set loadoptions ENABLE_INTEGRITY_CHECKS
bcdedit /set TESTSIGNING OFF
This should allow you to install your modified driver without it being blocked by Windows at each boot.
Yeah @chinobino that works too, but anticheat software will yell about it, like PUBG’s and Valorant… So no go there
Yep the anti-cheat software issues are another reason I recommend using an SLI motherboard - too many hassles.
Although I completely understand you wanting to use what you already have, it’s a pity that Nvidia aren’t a little more flexible.