I made a little formula which I run with and maybe useful to make comfortable yet quiet temps:
Basic Formula
(W + O)*1.5 = R x D x F
W = 1 point for each water block you want to cool.
O = 1 point for every OC'd/hot item you want to cool.
R = 1 point for a 120mm radiator section.
D = 1 point for a 30mm thick radiator and 2 for a 60mm radiator. (interpolate and extrapolate as required)
F = 1 point for using fans or 0.5 point for going fanless. (No bonus for push/pull though its nice).
E.g.
You have two blocks and 2 OC'd/hot items:
W(2) + O(2) = 4 x 1.5
So to balence the equation:
6 = 3 x 2 x 1
1x 360mmx60mm rad with fans.
Modifier
The
Modifier basically alters how cool and quiet the system runs, change it from 1.5 (minimum) to 2 (quieter) to 2.5 (pretty damn quiet) and then balence the formula in the same manner as done above.
(W + O)
x2.0 = R x D x F
Now the system is worth 8 points (4
x2) and would be balenced by 2x 240mmx60mm rads.
Hopefully that's confused everyone.
M&P
P.S. if you are looking into buying your own fans then static pressure is a more valuable stat than CFM when cooling radiators.
So the formula for fans would be
SP x (CFM / 2) = FV
Where SP = staitc pressure, CFM = CFM and FV = Fan value
Only joking, I don't really have an equation for that
EDIT: Added modifiers.