AIO and CPU Temperature Discrepancy

EngineerLife24 · March 22, 2023

Information:

I recently got a new AIO and case for my PC and was confused by the temperature difference between the CPU and the radiator itself. It's an Intel Core i7-8700K CPU (Overclocked to 4.5 GHz) in the HYTE Y60 case, cooled by the LS720 (360 mm radiator AIO) mounted at the top of the case. When running Cinebench R23, HWiNFO64 says the cores were between 69-74 degrees C for max temperature, and the CPU temperature reading by AISuite3 (ASUS motherboard software for my ASUS PRIME Z370-P motherboard) read a max CPU temp of 63 degrees C. However, the radiator never got hot. I touched the radiator during the run, and it never felt hot or even warm.

Questions:

Why is the radiator not getting warm, but the CPU is staying at reasonable temperatures? Is it a case of the AIO being thermally limited by the lid of the CPU? (I did not delid the CPU, nor do I intend to)

A bit more information:

I switched to the HYTE Y60 from my previous case because my last case had half of the front fans completely covered by a piece of tempered glass with a piece of metal on the other half; the piece of metal left less than 1 cm for air to come out of the case while the tempered glass did not allow for any air flow. I had the PF360 AIO (360mm AIO) from Silverstone installed on the front of the case, exhausting out, and I could always feel very hot air coming out of it. The PF360 stopped working when I switched cases, hence why I now have the LS720. I would idle around 50-60 degrees C with the PF360 even back when I first bought it (and I know it was making contact with the CPU because I took it off to check and see if the thermal compound had been spread by the AIO pressing down on the CPU). Still, it never got above 85 degrees C under load (I idle around 35 degrees C with the LS720). I got a Cinebench R23 score of 8926 with the PF360 right before I switched cases and a score of 8954 now with the LS720 in the new case. This is where my confusion is arising from: why did my PF360 always pump out hot air, yet the LS720 never does, even if I run back-to-back Cinebench R23 multicore runs?

Thank you for any insight you can provide!

Dukesilver27- · March 22, 2023

How do you configure the pump and fans? You know that those settings will affect cooling performance right?

PDifolco · March 22, 2023

1 hour ago, EngineerLife24 said:

Information:

I recently got a new AIO and case for my PC and was confused by the temperature difference between the CPU and the radiator itself. It's an Intel Core i7-8700K CPU (Overclocked to 4.5 GHz) in the HYTE Y60 case, cooled by the LS720 (360 mm radiator AIO) mounted at the top of the case. When running Cinebench R23, HWiNFO64 says the cores were between 69-74 degrees C for max temperature, and the CPU temperature reading by AISuite3 (ASUS motherboard software for my ASUS PRIME Z370-P motherboard) read a max CPU temp of 63 degrees C. However, the radiator never got hot. I touched the radiator during the run, and it never felt hot or even warm.

Questions:

Why is the radiator not getting warm, but the CPU is staying at reasonable temperatures? Is it a case of the AIO being thermally limited by the lid of the CPU? (I did not delid the CPU, nor do I intend to)

A bit more information:

I switched to the HYTE Y60 from my previous case because my last case had half of the front fans completely covered by a piece of tempered glass with a piece of metal on the other half; the piece of metal left less than 1 cm for air to come out of the case while the tempered glass did not allow for any air flow. I had the PF360 AIO (360mm AIO) from Silverstone installed on the front of the case, exhausting out, and I could always feel very hot air coming out of it. The PF360 stopped working when I switched cases, hence why I now have the LS720. I would idle around 50-60 degrees C with the PF360 even back when I first bought it (and I know it was making contact with the CPU because I took it off to check and see if the thermal compound had been spread by the AIO pressing down on the CPU). Still, it never got above 85 degrees C under load (I idle around 35 degrees C with the LS720). I got a Cinebench R23 score of 8926 with the PF360 right before I switched cases and a score of 8954 now with the LS720 in the new case. This is where my confusion is arising from: why did my PF360 always pump out hot air, yet the LS720 never does, even if I run back-to-back Cinebench R23 multicore runs?

Thank you for any insight you can provide!

I suppose HWInfo is giving you max temp on some part of the chip while AI suite gives you average temp of cores, there's often 10C difference

Reagrding rad temp it's not supposed to get that hot, hot water i only 40C some max and is sent to the rad (flow is on the borders) to be cooled by the fan airflow and the fin stack

So eventually the rad is just a tad above ambient, that's not really noticeable to the touch

Light-Yagami · March 22, 2023

Radiator will only reach the water temp. Water temp usually reaches between 28-31°C, depending on the load. It can be higher with smaller AIOs but with a 360mm rad, there's no way. It's normal that the rad doesn't heat up at all.. 8700K pulls sth like 140-150W under load? That's nothing for a 360mm rad.

You're basically limited by heat density of the CPU and thermal transfer between IHS and cooling block.

What you're experiencing is completely normal.