Expected Temperatures of a Watercooled 4090FE?

[Mysterae_]

Not sure how I ended up here, but this is a splendid thread

I had never heard of pump out!

However you arrive, you're welcome @dlockers! I'm just having break from all the house diy stuff but normal service will resume!

I had heard of pump out but never experienced it, part of me thought it may have been a myth - an excuse for crap or badly applied thermal paste. I know differently now!

 

[Mcnumpty2323]

Not read up on it
Or experienced it.myself
That looks like separation of paste components?
Is there silicon/silicone in the paste?

 

[srekal34]

Thanks for this post, and yes it's inevitable that it will happen again as I used the same MX-6 thermal paste. It's only a matter of time.

I'm going to order some Honeywell PTM7950 that you mention in preparation for the repasting. I've used liquid metal in a previous build and it was a pain, it's not going anywhere near the 4090!

Yeah LM is not worth it for couple of degrees.
When you get PTM, pop it in the fridge for ~2hours before applying, its much easier to apply when its cold(at room temperature it tends to stick to the foil and tears)

 

[Mysterae_]

Yeah gpu thermal paste looks terrible
Would say that's main issue
Though coolant temp seemed high before too
It may be worth ordering
Some of the Pastes mentioned
Just in case since you're rebuilding it with
Same paste as first time

Never used a reservoir with a filter
Does make me curious if it affects flow
At all

Yeah thermal sheet may be an idea
Think there's a few manufacturers making those now

You do bring a valid point - why was the coolant temp so high?

Something was restricting the flow in the computer like it had never done before. I even thought that I'd mixed up the in and out quick disconnects as that would affect flow tremendously, but the tubing going in to the computer was a lot cooler than coming out. I have some thermal images of this and as soon as I can get my thermal camera connected I'll share some images of this.

As for the reservoir and it's filter, I don't think it impedes the flow.

 

[Mcnumpty2323]

You do bring a valid point - why was the coolant temp so high?

Something was restricting the flow in the computer like it had never done before. I even thought that I'd mixed up the in and out quick disconnects as that would affect flow tremendously, but the tubing going in to the computer was a lot cooler than coming out. I have some thermal images of this and as soon as I can get my thermal camera connected I'll share some images of this.

As for the reservoir and it's filter, I don't think it impedes the flow.

I guess it's sort the main obvious issue first
Then see how coolant temp is
And look at that
Yeah in my head at least
If the filter impeded flow
The level in the reservoir would start rising
If coolant was leaving pump faster
Than returning to it

 

[wookiee87]

In all my time watercooling I've never seen that pattern of paste when removing a block. It was a brand new tube of MX-6 too.

There wasn't that much debris in the blocks to be honest, I expected something drastic!

Yeah its not the first time for me, i have a friend that had the same issue with his loop but his cpu paste had gone off, his 5900x was getting to mid 80-low 90's and wondered why, i kept saying you need to repaste and eventually he did, new mx4 beforehand and looked watery, but he used a bit too much, silver 5 to the rescue and temps maxing around 69c.

even the tiniest amount of debris is something you really dont want in blocks as it can promote growth eventually, though coolants are very good these days to stop that.

 

[Mysterae_]

I guess it's sort the main obvious issue first
Then see how coolant temp is
And look at that
Yeah in my head at least
If the filter impeded flow
The level in the reservoir would start rising
If coolant was leaving pump faster
Than returning to it

It's a shame I didn't integrate a flow sensor in to the circuit, I even have 2 spare from a previous build (Aqua Computer MPS Flow 200). I didn't want to fit one because of space constraints or having to use an Aquaero.

Thinking of scenarios, perhaps a poorly connected quick disconnect (or something else) impeded flow and the increasing temperatures exasperated the GPU core temperatures leading to the pump out. Totally surmising here.

Yeah its not the first time for me, i have a friend that had the same issue with his loop but his cpu paste had gone off, his 5900x was getting to mid 80-low 90's and wondered why, i kept saying you need to repaste and eventually he did, new mx4 beforehand and looked watery, but he used a bit too much, silver 5 to the rescue and temps maxing around 69c.

even the tiniest amount of debris is something you really dont want in blocks as it can promote growth eventually, though coolants are very good these days to stop that.

It's weird that you hear very little about something but as soon as I searched for pump out on 4090 I get loads of results! It seems it's known even on non-watercooled 4090s due to their high power load (+400W).

 

[srekal34]

Its also because the core is slightly convex and huge. Its not an issue on small dies like bare cpu.

 

[Mysterae_]

Finally managed to get some images downloaded from my thermal camera that I took before stripping the computer down. It picked a good time to require an update...

The is the rear of the computer, the inlet/feed is the quick disconnect at the bottom and the outlet is the quick disconnect at the top. The outlet is much warmer than the feed so at least I didn't mix them up - that would have been hilarious.

The image below is the reservoir and pump showing the warm water going in and out of the pump to the top of the MoRa3 radiator. The outlet of the radiator is the shiny thing just at the bottom of the pump. The water is much cooler so the radiator is doing it's job.

Below is the Heatkiller block for the 4090 - the top tube is the inlet to the block and the bottom tube is the outlet. There is definitely some heat absorption by the coolant.

This leads me to believe there was a flow restriction which meant the coolant hung around the components for longer than it should leading to a high coolant temperature. With the MoRa3 radiator being so damn efficient causing the delta of the coolant to be so large, it may have caused the thermal paste "pump out" on the GPU, each temperature cycle making it worse. Sounds plausible?

 

[Jay85]

Definitely thermal paste pump out, though i've never had this happen that does not look right. You've applied the same stuff back too!

Hope its not another strip down a few months down the line again man.

 

[Mysterae_]

Definitely thermal paste pump out, though i've never had this happen that does not look right. You've applied the same stuff back too!

Hope its not another strip down a few months down the line again man.

Indeed! I think it's inevitable that the 4090 will need to be repasted with something more appropriate. At least it's just the graphics card that will need it so not a total strip down.

Temperatures are back to where they should be - a benchmark run of FurMark 2 at 2560x1440 with a 438W load - core 47C and hotspot 54C. It's a shame the FurMark knocks out my secondary screen while it runs, means I can't see the stats on the fly.

I wonder how long it will last!

 

[Mcnumpty2323]

Themal camera very nice tool for analysing the loop

You have just about everything very nice build
I would definitely think of adding
A flow meter too
Temperatures tell half the story
When my cpu block was clogged up
Surprisingly little effect on Temperature
Was only because I added a 3080ti with active backplate
And couldn't figure out
Which ports were in and out on active backplate
By looking at the flow
I realised something else was up with my loop
As tested all 6 possible in/out combinations on the 3080ti

 

[Mysterae_]

Themal camera very nice tool for analysing the loop

You have just about everything very nice build
I would definitely think of adding
A flow meter too
Temperatures tell half the story
When my cpu block was clogged up
Surprisingly little effect on Temperature
Was only because I added a 3080ti with active backplate
And couldn't figure out
Which ports were in and out on active backplate
By looking at the flow
I realised something else was up with my loop
As tested all 6 possible in/out combinations on the 3080ti

It's amazing how useful a thermal camera can be, from diagnosing car issues, around the house to even PC cooling .

I'm considering adding one of the flow meters I mentioned earlier, depends if it can be connected to the D5 Next without losing water temperature. I wonder if AIDA64 would pick it up if just connected via USB. It'll be tricky to fit though with not a lot of space available.

It can be frustrating when something changes with your computer with no obvious reason as to why.

 

[Mcnumpty2323]

Not totally sure if aida64 would pick it up
Just using usb
Only a guess but can't see why not
Other devices use usb to report stuff
I use a tablet or any old android device
I have Laying around for aida64
But I have sensor wire for temperature to motherboard not usb
And just using a standard spinning wheel for flow
Lowered coolant level in distro too
So it's below the coolant return point
Gives me a visual on the returning coolant speed/flow
Might add a digital flow meter at some point though

Could you add flow meter on the external tubing to the rad?
Might need to lengthen the wires
But have seen someone in here forget who
They have all the wiring for fans and pump etc extended
To a mora
But they have used some sort of quick disconnect wiring plugs
So can detach the wiring and coolant tubing from the pc
If that makes sense lol

 

[srekal34]

D5 next has a header for flow sensor, no?
Just make sure you use old type of sensor. New Aquacomputer flow sensor(flow2/next) makes clicking noise and was the loudest part of the loop, was deiving me mad(that was after adjusting the propeller, out of the box I've heard it from another floor)

 

[Mysterae_]

Not totally sure if aida64 would pick it up
Just using usb
Only a guess but can't see why not
Other devices use usb to report stuff
I use a tablet or any old android device
I have Laying around for aida64
But I have sensor wire for temperature to motherboard not usb
And just using a standard spinning wheel for flow
Lowered coolant level in distro too
So it's below the coolant return point
Gives me a visual on the returning coolant speed/flow
Might add a digital flow meter at some point though

Could you add flow meter on the external tubing to the rad?
Might need to lengthen the wires
But have seen someone in here forget who
They have all the wiring for fans and pump etc extended
To a mora
But they have used some sort of quick disconnect wiring plugs
So can detach the wiring and coolant tubing from the pc
If that makes sense lol

In this build I wanted as few connections between the PC and the radiator as my last build had 5 (fans, Aquabus, power, quick disconnects x2) so went with only the quick disconnects. I gave in and added a USB connection between them to provide me with the coolant temp and pump and radiator fan speeds - that has proved to be invaluable here.

D5 next has a header for flow sensor, no?
Just make sure you use old type of sensor. New Aquacomputer flow sensor(flow2/next) makes clicking noise and was the loudest part of the loop, was deiving me mad(that was after adjusting the propeller, out of the box I've heard it from another floor)

Yes and no - from the D5 Next manual:

5.3. Connector “Fan” for fan or flow sensor -
Depending on configuration, this connector can either be used as a PWM regulated fan output with speed signal processing or to connect a flow sensor. Simultaneous use of both functions is not possible!

I'm already using this connector to control the 4x180 PWM fans of the MoRa3. Shame! Can't even connect it to the "Bus" connector as it's not on the list of compatible Aquabus devices. If I really wanted to have it I could reinstate my Aquaero controller but that would be a challenge to find somewhere to fit it .

 

[darket]

All this has made me want to repaste my 4090, temps have been creeping into the mid/high 50s for a while now. I think I'll just liquid metal as I've done with all my past gpus, never went off or pumped out.

 

[Mysterae_]

All this has made me want to repaste my 4090, temps have been creeping into the mid/high 50s for a while now. I think I'll just liquid metal as I've done with all my past gpus, never went off or pumped out.

Liquid metal will definitely make a difference but I think it was too big a risk for me. My 4090 stands vertically just like the PS5 that had many problems with liquid metal leaking out.

Good luck to you should you decide to do it!

 

[darket]

Liquid metal will definitely make a difference but I think it was too big a risk for me. My 4090 stands vertically just like the PS5 that had many problems with liquid metal leaking out.

Good luck to you should you decide to do it!

Thanks. All mine have been traditionally mounted so never had a issue, fingers crossed haha

 

[D1craig]

I may liquid metal my gpu aswell. Mine is lower class though - 6700xt. I've had pretty bad hotspot temps since I installed my blockbuster nothing stupid. 30C more than core temp but never higher than the 80Cs so haven't bothered. Just need to make some room to sort it out.

EDIT - if it goes wrong that's my upgrade excuse