Pci-e 3.0 card on a Pci-e 2.0 board with 2011 BIOS

Howdy. See if anyone here knows off the top of their head.

That time has come again; what with the demise of fglrx, the old amd vs nvidia / Wayland conundrum and new AM4 and Ryzen due out. I’m figuring it’s going to be upgrade time coming up.

I still figure for open source AMD is going to be the safer option in the long run, so the easiest upgrade to make first is a modern GPU that can utilise amdgpu / amdgpu pro, Am currently running a 5700 series card so an entry level RX 460 2GB GDDR5 ticks all the boxes and is good enough for what I need. Then I can snag an AM4 motherboard and Ryzen chip further down the line when the dust has settled down.

But then I thought of a possible fly in the ointment. Will a modern Pci-e 3.0 card run on an older P55 chipset board with a final 2011 bios flash (no more available)?

I’ve read Pci-e 3.0 cards run without problem in Pci-e 2.0 slots fine with no perceptible loss in performance, and Pci-e is backwards compatible. But what about that bios question??