how many radiators is best for multi cooling?

[p1que]

i am liquid cooling my gpu and cpu and was wondering if one 240 mm rad on the top is ok or if i should have a 120 mm on the bottom as well? What works best? is it worth the extra money for the extra fan and rad or no?

 

[GRUxTSAR]

Which CPU/GPU do you have?

 

[p1que]

amd fx 8320

EVGA GTX 970 http://www.newegg.com/Product/Product.aspx?Item=N82E16814487065&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=

 

[JackNaylorPE]

Based upon the standard design goal of 10C delta T....

At 1250 rpm fan speed, each 120mm of 30mm thick rad will net you about 60 watts of cooling, 73 in push / pull
At 1800 rpm fan speed, each 120mm of 30mm thick rad will net you about 81 watts of cooling, 98 in push / pull

At 1250 rpm fan speed, each 120mm of 60mm thick rad will net you about 63 watts of cooling, 76 in push / pull
At 1800 rpm fan speed, each 120mm of 60mm thick rad will net you about 90 watts of cooling, 108 in push / pull

A HW / DC CPU overclocked will generate 140 watts ..... a 290x about 300 watts OC'd .... MoBo block about 40 watts, pumps about 23 watts each.

A 4790k w/ two 980s all OC'd about 1 x 140 + 2 x 190 or about 543 say 550 watts.

Take 60% of that for the rads...so 330 watts. At tolerable noise levels (1250 rpm), you;d want at least 4 x 120 or about 300 watts of cooling..... 4 x 140mm would give you 332 watts with a 45 MM thick rad.

You can do all this with the rad size estimators here:

http://www.overclock.net/t/1457426/radiator-size-estimator