New GPU - Loop - Heat

[noobftw]

I currently have an i9 7900x and a 1080TI FE, both are overclocked, CPU is at 4.6Ghz.



All of this is running in a single custom waterloop with x2 Alphacool NexXxoS ST30 Full Copper 420mm radiators (Push configuration) and a D5 Pump. The case is a Dark Base Pro 900, one of the radiators is intake (front), and one is exhaust (top), only other fan in the system is an exhaust fan (140mm) out the back of the case.

Current System Temps while gaming:

Water Temp: 40c

Water Pump Speed: 2.9

Radiator Fans RPM: 1000/1100 RPM

CPU Temp: 62-72c

GPU Temp: 46c

Question, if I replace the 1080TI, which has a TDP of 250 stock (FYI my GPU is overclocked so will be higher), with the 3080 (TDP 320) or the 3090 (TDP 350), and don’t overclock the new GPU, (1.) will my radiators be able to handle the extra heat?

(2.) Will I have to increase my fan speed? By how much…

(3.) Will the water loop run hotter, how much hotter? Will it be too hot for the soft tubing I use?

(4.) Will the additional heat of the 3080/3090 heat up my CPU more than it is now?


Thanks in advance.

 

[MikeTimbers]

1) yes, 840mm of radiator is lots
2) impossible to say, but I would not expect any major change
3) possibly, can't predict how much. Not too hot for soft tubing IMO
4) again possibly.

You're looking for science when watercooling is often more like an art. Because I don't have your exact setup, I can not model answers to your questions that will give you hard numbers.

e.g.

The D5 is at 2.9. But what's the flow rate?
The fans are at 100/1100 rpm but what fans are they? How much airflow are they achieving?
What's the room ambient temperature? Do you have the window or door open or is it a closed room?

I don't know all those answers and I doubt you do so neither of us have hard data for every part of your loop.

Two 420mm ST30 rads is a lot of cooling but even Alphacool don't specify what the cooling capacity is. Because it depends on the fans, the ambient temp, the air resistance through the rad. i.e. a radiator outside a case with a given fan can be measured. Put the radiator in a case and the fans are now pushing air into or out of a case. Is it closed, restrictive, wide open? Are there exhaust fans? has the case been setup for positive or negative case pressure? To what extent?

I'm really not trying to be a Richard but every watercooling system is unique. You should be well within limits with two 420mm rads. If it becomes too hot for you, add fans to make it push/pull or put stronger fans in.

 

[Hewligan]

70-100 extra watts should be perfectly fine with those radiators and pump. You may need to turn the pump flow up 10-15% and same with the fans, if you really want to keep the same temperatures, but if you are okay with them rising a couple of degrees then I think you will find it works fine.

 

[noobftw]

1) yes, 840mm of radiator is lots
2) impossible to say, but I would not expect any major change
3) possibly, can't predict how much. Not too hot for soft tubing IMO
4) again possibly.

You're looking for science when watercooling is often more like an art. Because I don't have your exact setup, I can not model answers to your questions that will give you hard numbers.

e.g.

The D5 is at 2.9. But what's the flow rate?
The fans are at 100/1100 rpm but what fans are they? How much airflow are they achieving?
What's the room ambient temperature? Do you have the window or door open or is it a closed room?

I don't know all those answers and I doubt you do so neither of us have hard data for every part of your loop.

Two 420mm ST30 rads is a lot of cooling but even Alphacool don't specify what the cooling capacity is. Because it depends on the fans, the ambient temp, the air resistance through the rad. i.e. a radiator outside a case with a given fan can be measured. Put the radiator in a case and the fans are now pushing air into or out of a case. Is it closed, restrictive, wide open? Are there exhaust fans? has the case been setup for positive or negative case pressure? To what extent?

I'm really not trying to be a Richard but every watercooling system is unique. You should be well within limits with two 420mm rads. If it becomes too hot for you, add fans to make it push/pull or put stronger fans in.

The fans are Be Quiet Silent Wings 3, max RPM is 1500
Room ambient this time of the year varies between 25 -30c, both windows wide open-door shut, but it's a small room, gets hot quick.
The fans are in push configuration on the radiators, front radiator takes air into the case, then top radiator exhausts it, back 140mm case fan also exhausts air. The case dissipates air quite well, as I have modded it, the top radiator (exhaust) is unrestricted, while the front is for the most part unrestricted.

 

[D1craig]

I remember reading when I made my first loop that water temo shouldn't go past 40c as that's what the tubing was rated at. I never had temp sensors apart from gpu and cpu so I don't know how high my water temp got but I'm sure it was higher than 40c and I had no problems. It was 2 rads in an evolv itx case.

I would imagine your gpu temp will be a fair bit hotter than it is now with a 3080 or 3090 which will likely use more than stated. Should still he easily managed though.

 

[Gavster]

Just for a bit of a reference point these are my temps after a hour and a half on PUBG, my room is small, door closed and the window open with the front panel removed.



I have a slim 360 radiator top mount with the fans set to exhaust and a front 240 radiator with the fans set to intake, 3080 FE with a monoblock in a Fractal Design S2 Vision case, EC-TEMP2 is my coolant temp.

https://www.overclockers.co.uk/forums/threads/first-custom-loop-with-a-3080fe.18916643/page-3

HTH

 

[MikeTimbers]

As a baseline, work out your best cooling possibility:

case covers off
fans on full
pump on full

run your most intensive workload and record the temperatures

If they are unacceptable - particularly the coolant temperature - you do not have adequate cooling power so you need to improve it. More powerful fans and/or bigger fatter radiators.

The only other option I can think of is an air-conditioner for the room.

 

[Robzere31]

Just to add I have the same case as you & find the airflow with it terrible.
To the point I modified the top of it which dropped my temps by around 10-15c under load.

Have a look at my build thread to see the details if you interested.

 

[MikeTimbers]

That case does look air-restrictive. Those sorts of solid fronts are just so badly thought out. I had a Fractal Define Design S which had vents all the way round the front but as they were all only around an inch long the flow was near non-existent even with good fans. I modded it to be a mesh front and cooling improved noticeably.

 

[Drumroll]

Should be fine. Thicker rads would help, but not as much. More rad area would help more, but the last place you could try is the back exhaust and a single 120 or 140mm rad is not worth.
You're limited by the case which, despite the quality, isn't the more efficient regarding airflow/rad position.
A cheaper solution would be swap the case, keep your gear, and look for a case that would allow your rads to perform at their maximum.
Few O11 XL B-Grade for 150ish, which is a good buy. Mine was new, only small damage to the box.