Pump placement?

[Callsign_Vega]

Using an Iwaki RD-30 on a sub-zero liquid setup, is there any issues with putting the pump after the CPU and GPUs restriction versus before the restrictions? (3x 1/2" tube loop with 3-way connectors on either end for splitting/combining)

This would be to get the coldest temps and not dump any pump heat into the liquid before it reaches the components. Would this be too restrictive for the RD-30 to "suck" liquid through all of the components rather than "push" the liquid through the components? I am unfamiliar with the way pumps operate sucking versus pushing pressure.

[Church]

Most centrifugal pumps for best performance like incoming inlet to be as unrestrictive as possible. Also they don't suck, only push, and might be damaged, if ran liquid less. Always put reservoir before pump. Don't know if subzero something will change (doubt it) but for generic liquid cooling loops order of components (above res before pump rule above) doesn't matter, as with good flow each loop component heats up or cools down liquid too little to care about that, so best is connect all of them with routing tubing as shorter/simpler/with less tight bends.

[PiLsY]

Thats the first time I've ever seen anyone ask "would this be too restrictive for an Iwaki?"! The answer is you could use that Iwaki to pump custard around that loop and you'd still have no restriction issues :lol:.

Regards the heat - I would be tempted to try res > pump > rad if you want absolute minimum temps. Even though they do put out a bit of heat it won't affect water temp by much. Somewhere between 1/4 and 1/2 a degree celcius. You may see 1c lower at the cpu if you feed it the absolute coldest water in your loop compared to the hottest water.