I bought myself the Aquacomputer AMS 120.4 radiator (aluminium fins) recently and had it set up in a single loop, one AMS installed at the top and the other at the bottom inside my STH10.

Both were fitted with 8 fans, in push-pull configuration.

Now, the weird thing is ....my top radiator seems to be the only one cooling my rig as i can feel hot air emerging from it. The bottom radiator stays cool throughout, absolutely no hot air at all even when i stress test my gpu with furmark.

This is my loop:

pump - radiator 1 - gpu 01 - gpu 02 - cpu - radiator 2 - reservoir - back to pump

The AMS radiators have 3 inlets and 3 outlets. The hot water goes into the inlets and exit through the outlet. I am assuming there is no difference (cooling wise) in which one of the 3 inlets i uses and which one of the 3 outlets i uses.

The AMS radiators i bought are single circuit.