What radiator size works for cpu and gpu in a custom loop?

[Luke47]

I’ve finally got my hands on the last few components for my custom loop, but I’m second-guessing my plan to use a single 360mm radiator for both the CPU and GPU. My gut says it might not be enough for quiet operation under load, but I really don’t want to modify the case for more mounting points.

[AaronHC]

I did something like that once. 360 for CPU and GPU in a mid tower. Idle was fine, under games the GPU cooled but the fans got loud. I ran push/pull with solid SP fans, but it never got quiet enough for me. I ended up dialing down the GPU clocks and using a more aggressive fan curve, which helped a bit but the noise was still there.

[RileyL]

If you really want it quiet without adding another radiator, you need the right balance: good rad, strong case airflow, and careful fan curves. In my experience the pump head matters; if you hear the pump you’ve probably got a bottleneck somewhere. A quick test I did was swapping to ultra quiet fans at moderate speed; temps rose a notch but noise fell a lot. Not perfect, but it taught me to live with the tradeoff.

[Paisley_T]

Have you measured temps under load with that loop?

[Michael.J]

One time I drifted off topic cleaning dust and re-seating the block, thinking noise would vanish. It didn’t fix the heat issue, but it reminded me to check airflow and radiator orientation. If your case can move more air front to back, that can help you stay with a single rad and reassess later.