Thinking of buying one 5770 now and one later to crossfire to help when star wars comes out. I have this case http://www.nzxt.com/new/products/classic_series/alpha and with just an exhaust fan and a side fan that doesnt seem to blow very hard, think it may be set low rpm and not sure how to change. Not the best air flow case but I'd like to not have to buy a new one.
Which type of cooling design would you recommend for crossfiring 5770's? The hawk sure can be a beast but it seems like having two might limit the cooling of the top one, i dont know
Does your motherboard allow you to leave an open slot between them? If so cooling shouldnt be an issue, if it doesnt you should consider the Sapphire Vapor-X cards, it should help keep things down at reasonable temperatures.
To be honest 5770 is pretty cool card no matter what heatsink design you will choose, i run xfx 5770 crossfire with reference coolers (blower design) and pretty happy, but i've had one with egg cooler before, also from xfx and it was even cooler and more quiet, but it didnt look as cool though. So my personal recommendation: get xfx, any cooler design, cause of their customer suport and double lifetime warranty, which means that if you resell your card(s) second owner will also have lifetime warranty. Just keep in mind that with crossfire configuration its good to have nice air flow inside of your case.