Hello, i bought a XFX 7870 DD 2gb graphics card. I think that i remember reading somewhere that some of the XFX 7870 cards have a reference PCB and some don't. How will i be able to see if my 7870 has a reference PCB so i can fit a water block? Also are there any water blocks out there that will fit the XFX 7870 DD 2gb if my card dose not have the reference PCB? Thanks