First time water cooler - CPU temp too high

[ampereira]

I was using a 120mm AIO watercooling kit from Artic but decided to upgrade to the EK Fluid Gaming 360 with a GPU block.

 

Firstly I installed only the CPU, leaving the GPU out of the loop as I didnt have my 1080ti at the time. However, I noticed that my CPU (8800K) even at stock speeds failed the OCCT stress test after 10 secs due to high temps... I though there was air in the loop or that the block wasnt sited properly so I thought Id rebuild the loop once I got my GPU. And so I did, everything from scratch and closely following the kit instructions but my CPU temps are still way too high. The GPU, however, was colder than on air cooling... I also tested with the pump and all fans at max speed.

 

Any guesses? Is my CPU block at fault?

[Boomwebsearch]

Could you please post your system's temperatures using a tool such as OpenHardwareMonitor? Water cooling is not always going to give you lower temperatures than an air cooler and that would depend on the air cooler and the water cooler which you are trying to compare.

[ampereira]

Here's a screenshot that OCCT failed (CPU stable overclocked ok with my previous AIO) after only 5secs. You can see temps of CPU/GPU in here.

[SuperCloneRanger]

either the block is not mounted correctly or something is blocking flow through it. first i would reinstall the mounting hardware and block making sure to use the correct standoffs as this can be done without draining the loop. precisely follow this instruction video.

If that does not help you should remove the block and check for obstructions, place the block under the tap and run water into one hole, it should freely flow from the second hole.

[ampereira]

I reseated following the exact instructions and the problem persists. I think the flow is ok because I vaguely remember checking it when I cleaned the block with distilled water, but I guess I'll have to drain the loop again to check that...

[ampereira]

I tried everything so it must be a faulty block right?

[For Science!]

29 minutes ago, ampereira said:

I tried everything so it must be a faulty block right?

I think your VCORE (1.41 V) is insanely high for the clock. I assume yuou have automatic voltages enabled and this is pumping too much heat. If the bnlock wasn't mounted properly,  your idle temperatures would also be quite bad.

 

If you want a close comparison, I would recommend you to run RealBench Stress test that puts load on both the CPU and GPU. In my case with a delidded 8700K @ 4,8GHz and a 1080Ti, I had 75 degrees on the CPU and 54 degrees on the GPU. This was in a custom loop with a 360 mm radiator in a small form factor case.

 

[ampereira]

It happens even at stock speeds.

[For Science!]

14 minutes ago, ampereira said:

It happens even at stock speeds.

But are these "stock voltages", auto voltages from any motherboard is not great at keeping the temps in check. On my chip I can easily go to 5 GHz with 1.36 V. I would heavily recommend you dial in your VCore manually in the bios.

[ampereira]

But why didnt this happen with the my previous AIO? That's what it's getting me confused....

[For Science!]

11 minutes ago, ampereira said:

But why didnt this happen with the my previous AIO? That's what it's getting me confused....

When did you do the test with the AIO? and did you use OCCT then too?

[ampereira]

I tested before installing the new loop to compare it using the same OCCT tests.