[ysh]

DirectX 12 capable GPUs are all UEFI/Legacy (in case of some 600 series cards from NV, a vBIOS patch may be needed for UEFI support), exception to that are some AMD ones that support UEFI only (no legacy code in vBIOS).
NV is Legacy/UEFI, however OEM cards may be different than regular ones.

I read you can add Legacy support to AMD cards by modding it's vBIOS (I don't know how to do it though).

Basic way to check if your card has UEFI support is to load GPU-z (it shows if card is UEFI capable).

PS. I should add, "legacy" cards will work in UEFI boards - they simply can't do GOP for fast boot.

Sorry I know the post is too old but maybe someone find this useful, Asus P5Q deluxe has actually EFI BIOS !
http://www.xtremesystems.org/forums/showthread.php?200109-Modded-ASUS-P5Q-Pro-Deluxe-Premium-BIOS
View attachment 2464751

 

[Mr. Hyde]

I found this decade old setup in a original HAF 932 and was thinking about bringing it back to full glory for one last run, has 8GB ram and the Q9400. I still have enough water cooling equipment from builds to do 3 custom loops still laying around, so may give over clocking the CPU a shot.

Question is this still has the old HD4870. I was thinking of putting in a RX570 or RX580... What are the chances here of those working with the BIOS?
Main purpose would be to use it as a secondary machine for editing videos (Davinci Resolve).

Thanks!

Edit: I see someone has posted a link to an UEFI supported BIOS...

 

[silv3r]

Hi, guys! After finishing up with my x870e, I've decided to go back in time with my Asus P5Q Pro. I would be interested in tweaking the timings a little bit. Hope it works.