With more surface the overall speed of the air going through the rad is lowered wich i belive upps the heat removed per ccm of air. 10c delta is alightly high, so i will ike to stay below that. My 14cm yates are capped at 1000rpm so i cannot just upp the fans forever to ocmpensate. The current rad kan handle my simple e5200\3870 in its sleep atm, but the idea is more in the direction of a quad an maybe som 4870x2 ish. Every 10% i can get is 10% i can use to turn down the fans again to that inaudible area again...