Thanks for all the input.
Looking at my motherboard - Gigabyte Z68AP-D3 Rev 1 it looks like I might have a problem with those graphics cards since there isn't a UEFI bios update. Not really even sure what that means but I think those gfx cards will only work on the Rev 2 motherboard.
Well the fact that there isn't an update may well mean that it will be ok.
I have googled I can't find any mention of any NVIDIA release failing to work with that particular board.