Very nice Boom, just installed my 290X Tri-X but got the non-OC one.
Cheers bud. If you have the Tri-X same design as mine, you can just flash to the OC bios with no problems. My cards are OC but default OC bios on my cards was something like 1010 core / 1250 memory. I just flashed using the latest OC Bios from Tech Power up.
290X TRI X OC Bios here - http://www.techpowerup.com/vgabios/151774/sapphire-r9290x-4096-131212-1.html
Download the rom. Rename it to new.rom (For example)
Create a bootable USB stick with DOS. Use latest ATI flash put it on USB stick along with the bios
Boot into the USB stick dos mode and use command.
atiflash -p -f 0 new.rom