It’s your water temps which are important so the 40 degrees your seeing is okayish, not great but not bad.
I have 9900k and at stock you will find motherboard can actually Chuck a lot of voltages into them at auto, combine with the in crappy general IHS and it’s a recipe that at stock with a demanding game you will see spikes even under water. Problem is not the loop, its the heat transfer from the a relatively small surfaced area CPU through crappy IHS design, through the TIM into the block.
If you want to reduce CPU temps I would look at dialling in manual voltage. The stock voltage curve account for the absolute bottom barrel CPUs, such as mineand even then pump excess voltage in. I would also ensure the mounting all looks okay.
I agree with this. A lot of motherboards throw extra voltage into a 9900k to ensure stability when it isn't needed at all and that just turns to heat. Auto motherboard settings don't do things justice, it's all set for the lowest common denominator in terms of hardware as Radox has unfortunately experienced. Add the horrible IHS and you get a hot little beast. If I were you I'd remount the waterblock just to make sure all is well, and then dial in a manual voltage for stock clocks if temperatures are your main concern.
Just for comparisons sake, I have a 360, 280 and 140 radiator in my loop. My water temperatures tend to sit at around 31-32 degrees when gaming with my fans running under 50%. That's with an overclocked 9900k but an undervolted 3090. My motherboard VRM is also watercooled and I do have a gpu backplate cooler that will add some extra heat into the loop.
I wouldn't be too concerned with 40 degrees in the loop though, it's a little higher than I'd like but that's for my specific set up with my components, ambient room temperature, air flow conditions etc etc. It's certainly not going to cause any problems.
a club that could have kept its membership offer!
