card crashing when not in uefi mode

[supermotolew]

I have 2 saphire 280x cards they where working perfectly in crossfire until today I've chopped and changed and tried each card on its own in uefi and not and one card makes games crash on loading if uefi is not selected and in crossfire games are ok if both cards are booted in uefi I know which card is the issue but have no idea how to fix this or why it happened

 

[supermotolew]

anyone ? I would like to buy a bigger psu today but I wont bother if one is shagged .

 

[Michaeljcox24]

Have you tried one at a time and ran some strenuous benches like heaven and valley?

 

[supermotolew]

Yep tried all combos 1 at a time with the switch on and off 1 card is perfect the other crashes at the end of loading screen if the switch is off

 

[supermotolew]

I guess its no biggie if I just always run it turned on is there any downside to this ? Can I still ramp up card