3090 + i9 9900k Watercooling

andrewr2019 · 15 Jan 2021 at 14:45

Afternoon,

I've currently got a single loop setup cooling an i9 9900k, and a Zotac Trinity 3090 both at stock. I've got a 360/30mm and a 240/30mm radiator inside a Corsair 500D SE case handling this, and currently under load this keeps the CPU to between 60/70c and GPU under 50c and the coolant temp stabilises at around 40.

I'm wondering that if I were to update my case, would adding two or three thicker 360mm rads have any impact on the temperatures of the GPU/CPU?

Currently I'm using a Corsair XD5 pump, both rads are Corsair XR5, a Corsair XG7 GPU block and the XC7 CPU block.

andrewr2019 · 15 Jan 2021 at 16:14

Seeing as my GPU was running mid 70s on air I was pretty happy to see the improvement down to 50s

andrewr2019 · 15 Jan 2021 at 16:32

Everything is at stock.

andrewr2019 · 15 Jan 2021 at 16:40

I tried overclocking mine previously on an AIO to 5 on all cores, but had to up the vcore more than I'd have liked to keep the temps below 95! I suspect I didn't win the silicon lottery with my chip.

andrewr2019 · 15 Jan 2021 at 16:44

I'm hitting high 60s on Call of Duty Cold War on the CPU at stock, so not sure about OCing just yet. That's why I was curious if bigger rads would make a difference.

andrewr2019 · 15 Jan 2021 at 16:59

Thanks! I've heard a few things about having an i9 and 3090 on the same loop is going to cause a lot of heat to manage

andrewr2019 · 15 Jan 2021 at 22:07

SirConfused said:
With that kind of rad area, especially 30mm rads you're in the diminishing returns territory. You could get slight temp improvements but realistically you'd just be looking for fan speed reduction beyond your current setup.

If the GPU is under 50 then you're not going to see any throttling because of it and the CPU is just down to the block and voltage you have to cram through it to get your desired clocks.

I meant to say the gpu is under 60. But I don’t think that changes your point in any way as it’s still way cooler on water than it was on air.

andrewr2019 · 16 Jan 2021 at 22:44

koooowweeee said:
Temps seem high for a stock CPU. I would expect high 40's low 50's then up to high 60's when highly cooked.

This is my thoughts too. If I run prime95 or cinebench then it runs mid 60s at 100% load, which doesn’t seem that bad. It’s when the 3090 is under load too the temps of the cpu go up to the high figures, which is why I suspect my rads are potentially struggling a little.

andrewr2019 · 17 Jan 2021 at 11:52

Thanks for the advice everyone!

I left the thermal paste on the CPU block that Corsair provided, so I don't really know how good that is either. I think you're right in that I could try reseating the block, but I'll wait till next time I drain the loop to do that.

I'll try adjusting the voltages as well and see if that helps.

andrewr2019 · 17 Jan 2021 at 11:59

Radox-0 said:
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 mine and even then pump excess voltage in. I would also ensure the mounting all looks okay.

Out of curiosity what voltage have you set for your 9900k?

andrewr2019 · 17 Jan 2021 at 13:45

I've had a little play this afternoon with mine now.

I've dropped the voltage to 1.28, and played with the fans a bit and on COD Cold War I've now seen the CPU temperatures drop from 69/70 to 59/60 and GPU has dropped to 50. Water temps also seemed to average out between 31/32, so that seems a lot better than it was. I think that's telling me I was wrong about the radiator capacity as well, so maybe I'll save myself a little bit and not go down the new case route just yet. Unless of course I get bored.

I think I'm with Radox-0 in the garbage chip category though.. if I remember rightly I had to up to voltage way past 1.35 to get things stable on 5ghz on all cores

andrewr2019 · 17 Jan 2021 at 20:23

Radox-0 said:
Nice! I mean nice on the temp drop part, not the fact your in the same club as me a club that could have kept its membership offer!

Still going to be the lottery I expect. Mine is RO, infact I only picked it up in Dec for £310 after getting rid of my 8700k for £270. Manufactured in 2020 work week 43, so pretty late last year yet its still a potato. Yet your not wrong either, was banking on it being buying pretty late would luck out. Alas not the case.

To be honest though even at stock I’m happy with the performance of the 9900k so I’m not overly bothered at this point. I got mine 2 years ago.. OEM not retail. I was wondering if they binned the better quality chips for retail. Probably not but it went through my head.