hans_glans

What do you mean by performance decrease? Caused by what?

Is there any way to not have testmode on?

Yes, highly depends unfortunately.

With WinDbg or IDA? Is checking the highest winver in the INF file and replacing it's hex value in the sys file with one version earlier the correct approach?

I think I got it but can't try myself. Just tell me if its correct please: For 472.12, we know the supported version is 17134 which is "42EE" in hex. After removing the OS requirement from the INF file and installing the resigned driver and getting error 43, we copy nvlddmkm.sys from the folder, and instead of "42EE" we put "3FAB" (16299), put the file back in and (possibly with test-signing and disabled integrity check) reboot. Correct?

But basically it is: - install driver with modified INF (-> error 43) - change respective OS hex value in nvlddmkm.sys correct?

No, it goes back to the initial problem in this thread. 3070 is only supported from 1803 onwards, irrespective of the driver. I'm just wondering which hex value in nvlddmkm.sys has to be adjusted after modifying the INF file.

Which hex should be edited for a 3070 on 1709?