Kind of a silly question but... I picked up this Hyper TX3 HSF and in came with a fan that runs at 2800rpm @ 54.8cfm., but also bought another fan that runs at 2500rpm @ 43.5cfm. So my question is... which fan do I make the intake (blowing through the HS into the other fan) and which one do I make the exhaust (blowing away).
It's easier to push air from an obstacle free environnement into the heatsink also the exhaust need to stress more since it got less airflow with all those heatsink fins that reduce the passage of air throught it. I'd put the one with best airflow as exhaust, the other as intake. But there won't be a noticeable difference.