EVGA GTX 670 FTW SLI

Greetings!

Hopefully someone can give me some solid advice on this! I'm currently running:

Case: Azza Genesis 9000
Mobo: Sabertooth Z77
CPU: i7 2600k @ 4.5 cooled with Hyper 212
PSU: OCZ 1000W
GPU: 2x 670 FTW 2gb SLI
RAM: 16gb G.Skill ripjaw 2133mhz


Right now everything is running good and for the most part very cool, but as this is a new system I'm being OCD with temps. Everything is mounted reverse ATX style, CPU doesn't break 70c ever, BUT! The 670s the top one will occasionally pass 70c and from my understanding the card will downclock itself slightly when that happens. I have a custom fan profile that will ramp up to drop the temps, but these cards will scream at 70+% fan speed.


Now my question is I noticed that these cards vent heat out of the rear of the card and honesty not 100% sure if all cards do. I just ordered a corsair h100i to replace my hyper 212 (OCD and can't seem to be content without spending more money, lol). I plan on mounting it to the top of the case but if these video cards pull air IN from the case and exhaust out of the back would I be better off going to normal ATX so the fans on the bottom of the case pull fresh air in and blow it right into the video cards?