Very much depends on the AIRflow thru your case. If you have a none reference GPU then case temps will be higher and need extra exhaust fans. Case temps are never lower than ambient temps so I have my top mounted rad fans pulling air into the case. I have tried it both ways and found an 8-10C difference however my ambient room temp is air conditioned.
Test by trying it one way and record your CPU temps under load, then switch around the fans and check the differance.
Do this prior to any Overclocking.
I'm not familiar with the Corsair 4000x rgb case however from what i can gather the fans are 120mm and if possible I would have rear fan changed to 140mm ML fan which are quieter under load. I also changed my rad fans to ML with an improvement around 6C and much less noise.
Yea but I feel like when you front mount it only airflow goes to the radiator and not my other components but with it top mounted exhaust the only different will be like 1 to 3 degrees and it’s cooling my cpu and getting rid of all he got air while my cpu is still getting amazing airflow
The air passes through the radiator. It does not get trapped there, but... you could make it to where air struggles to pass through the radiator, if you really want to:
Just replace the rad fans with some crappy 10USD ones - done. Or just use fans not designed for moving air through most hybrid cooler's radiators, like those Corsair QLs for example.