420 (45) vs 480 (60) Performance Difference?

[Shadowman]

I currently have a Phanteks Primo case which can take up to  2x 480mm radiators am currently water cooling a i7 5960x and 2x Sli Geforce Titan X's with a 480 radiator and know want to get a 2nd one. Know i was looking at a 420mm radiator from EK the EK CE 420  the thickness is 45mm know compare this to a 480mm, 60mm thick radiator how much difference in performance would it be? I understand the 480 might be better because of the thickness even though the 420 will have bigger surface area but thickness is only 45mm.

[W-L]

3 hours ago, Shadowman said:

I currently have a Phanteks Primo case which can take up to  2x 480mm radiators am currently water cooling a i7 5960x and 2x Sli Geforce Titan X's with a 480 radiator and know want to get a 2nd one. Know i was looking at a 420mm radiator from EK the EK CE 420  the thickness is 45mm know compare this to a 480mm, 60mm thick radiator how much difference in performance would it be? I understand the 480 might be better because of the thickness even though the 420 will have bigger surface area but thickness is only 45mm.

Longer rads tend to perform better than shorter thicker ones so if you can fit the 480mm that would be ideal. 

[hugemon]

A 420 rad already has more area than a 480 rad.

 

You must consider that you multiply 420 by 140 to get the area while you multiply 480 by 120.

Which leads to 420 Rad having 58,800 mm2 area and 480 rad having 57,600 mm2 area.

 

So a 420 rad is better than a 480 rad even if they are the same thickness.

 

But you have to be careful when choosing the 480 rad for the bottom of the Primo because a radiator with width less than 125mm will fit on the bottom. If you are considering getting 420 and moving your existing 480 to the bottom than you must check the 480 radiators width.