Motherboard won't post with GFX card in

[Kanoe]

This is going to sound rather strange but....

I have a Supermicro X8DAi motherboard with 2x X5650's in it that wont post when I put my R9 295X2 in it. (1200 Watt power supply to give it all the juice it needs)

The system powers on, the gfx card lights up, all the fans spin up, the green power indicator LED on the motherboard shows constant on but it doesn't post or give beep codes.

If I take the gfx card out and turn the system on then it posts with the beep code for can't find video adapter.

I'm like 99.999% sure the gfx card is OK as it came out of my other rig and im pretty sure the motherboard is OK as it works without issue with a R9 280X.

Any ideas although I do admit that I think this is something I will not be able to resolve.

[kalniel]

Check for bios updates - you may need one to work with newer cards due to new firmware models or incompatibility with PCI-E 3.0 cards. The 280X is quite a bit older.

[Kanoe]

Already at max bios version but thanks for the suggestion. The card was operating in a PEG 2.0 x16 slot in my last mobo. I thought that was the beauty of PEG that it is backwards compatible. If I can convince the wife to let me borrow her R9 290X to test with I could see if it would work with newer cards but even if it does or doesn't I'm not sure it gets me anywhere.

[AGTDenton]

I tried to download the manual but Supermicro's website is dead slow and times out.

Its possible in the BIOS there's a configuration option to specify exactly which PCI or PCIe slot # you have connected your graphics card to.
Sometimes the auto setting doesn't work when you have multiple cards installed as one causes it to error, so if its set to autoscan for a graphics card, try changing it to the exact slot number.

EDIT: Ok I've downloaded the manual from the US site instead, the option I was thinking about is located:
Advanced > Boot Feature > Boots Graphics Adapter Priority

[Kanoe]

Yup, tried altering those settings and it doesn't make a difference. Going to play some more. Feels like I'm sooo close

[AGTDenton]

assume you've tried a different slot if available?
I've had graphics conflicts with RAID cards before, the Graphics card would only work if it was in a lower slot # to the RAID card. Without the RAID card it worked in any slot.