Keeping the XPS730 case with GTX570 SLI
. Use 2 reference cooling GTX570s
. GTX570 Card 1 installed in bottom (green) PCIex16 slot
. GTX570 Card 2 installed in top (green) PCIex16 slot
. Current PCIex1 sound card to be relocated to the middle (green) PCIex16 slot (currently occupied by the GTX260). The sound card looks short in length enough not to block the intake fan of GTX570 Card 1.
See pic 1 below. As I see it, airflow has no problem.
But you need to check 2 things:
. check your XPS730 User Manual for lane allocation when the three PCIex16 slots are occupied.
If you can get x16/x8/x8, then it is OK.
If you get x16/x0/x16 or x16/x16/x0, then it is no good.
. physically move your GTX260 to the top PCIex16 slot to see if it interfere with the motherboard's USB headers (as circled in red in pic 2 below). You might need to bend down the cables a bit to make fit. It it does not, then it is very likely the future upper GTX570 will not as well.
A new case (Corsair 800D or HAF-X) for a GTX590
As I pointed out earlier, the reference cooling of the GTX590 is bi-directional. The hot air exhausting out of the front of the card poses a challenge to most (if not all) cases as most cases use front air intake which basically runs against the hot exhausting air. This bi-directional design is also used in the HD6990. I have actually raised this issue in both ATI and Nvidia forums but no user of either card has commented on the difference of temp between the 2 cores. Perhaps it is because both cards were only released recently and so no one has noticed this issue yet (?).
As for Corsair 800D and HAF-X, I would rather prefer the HAF-X. Both cases will have the above mentioned challenge but the HAF-X is better in the sense that it has the side panel fan (230mm) and the VGA card holder fan (80mm) to supply fresh air to the GTX590's intake fan (and possibly to the CPU heatsink fan as well--see my analysis below).
My analysis here using a HAF932: http://www.overclock.net/air-cooling...n-typical.html
(As we are moving away from the PSU topic, perhaps you can start a new thread in the Case or Air cooling forum.