I'm running dual XFX R9 290x (R9-290X-EDFD) cards on a Gigabyte 990FXA-UD5 Rev 3.0 mobo. The two cards are currently air cooled and slotted in the PCIe 2.0 16x slots on the board. I am planning on upgrading the cooling on these cards using 2 Corsair H55 closed loop coolers and 2 NZXT G12 adapters. Admittedly not a lot of games take full advantage of Crossfire but so far this setup has taken just about everything I throw at it. Because of how close the 2 16x slots are on this board (the two cards have MAYBE 3mm space between them) I am planning on moving my secondary card to the 8x slot on the board to allow for better airflow and to accommodate the water block. My question is, if the secondary card is in an 8x slot, will that downclock the primary card to 8x? Or will it still run at 16x? I know I will suffer a performance hit running the card in an 8x slot, how bad will it be? The Corsair H55 is 60 bucks, so I'm a little leary about spending the money on 2 of them if I would be better off going with a single card rather than suffering a performance hit in Crossfire mode. And before anyone suggests getting a new card, I've considered that. Until I searched around. Thanks to the cryptocurrency push, GPU prices are absolutely ridiculous right now. I'll stick with what I have until I get a game that won't play on this setup (which hasn't happened in the 4 years I've had these cards) Any help will be great. Thanks!!