I'm looking for a bit of advice.. Currently I have 1 EVGA GTX 670 Cheesecake in my rig, along with a AMD FX-8370E CPU both of which are watercooled. I only have a dual rad/single pump setup (they cool fine now, even when OC'd)... There is a MSI 7990 with a waterblock on available for £265 and then sell my 670 with block for I would hope £150+ so it is costing me only £100, give or take for the 7990. OR I can buy another 670 for around £100, plus a block for £60 and backplate for about £30, costing me £170, then my worry will be that I would need a bigger radiator as there are more blocks to go through and two cards to cool. I know the 7990 is 'Dual GPU' too, would I also struggle to cool that on my current setup? What would the performance differences be between the two setups?