RTX 3090 High GDDR6X RAM Temperatures of 110deg C

[TransAmDan]

Hey Dan!

I literally joined the forum just so I could get a better look at your images! I would be *highly* interested in the drawings and dimensions you have. I may be able to have a friend mill it out of a block of copper.

Anything you'd change on your design?

Hi,
I am planning on making 3 more asI have a couple more 3090's in need of modding. I'll get it drawn up, currently building another mining rig. I probably wound't change much, maybe extend some of the metal strips to cover a couple more IC's in the corners of the ram chips.
It would be perfect to get it milled out. You probably coulld use aluminum which would work out a little cheaper. The heatsink on the back i used was 4inches square this covered all the RAM chips. Maybe this could be bigger.

 

[Omikron]

Killer! Once you post your final I'll get the dimensions over to my colleague who runs a metal shop and see what he can mill out! If the cost isn't crazy maybe I could send some your way as well.

 

[Nelly]

I thought I had high temps on my PNY 3090 running at 86°C with a 1100 Meg memory overclock
The backplate was hitting 72°C above the GDDR6X chips on my thermal camera
I added a heatsink and 80mm fan as shown using 4 of the existing backplate mounting screws and some cheap 2 W/M/K heatsink grease
This has reduced the RAM temps to 68°C
I was not brave enough to remove the backplate on a 2K card
Seems reliable as has been going for 9 days now without a crash, I will be fitting a 120mm fan this weekend as the 80 is a bit small but all I had in spares box

 

[TransAmDan]

I thought I had high temps on my PNY 3090 running at 86°C with a 1100 Meg memory overclock
The backplate was hitting 72°C above the GDDR6X chips on my thermal camera
I added a heatsink and 80mm fan as shown using 4 of the existing backplate mounting screws and some cheap 2 W/M/K heatsink grease
This has reduced the RAM temps to 68°C
I was not brave enough to remove the backplate on a 2K card
Seems reliable as has been going for 9 days now without a crash, I will be fitting a 120mm fan this weekend as the 80 is a bit small but all I had in spares box

Nice results, thanks for sharing. Sounds like the PNY has a better design that the FE cards. That's some great results there. I only have FE cards, but I have a friend with MSIs and your solution could work for him too.
Good luck with the 120mm fan addition. You already have amazing results, and it going to get better.

 

[Nelly]

Nice results, thanks for sharing. Sounds like the PNY has a better design that the FE cards. That's some great results there. I only have FE cards, but I have a friend with MSIs and your solution could work for him too.
Good luck with the 120mm fan addition. You already have amazing results, and it going to get better.

Thanks Dan, I was just too scared to strip a 2k card with my clumsy fingers.

 

[Nelly]

Looking at you results your copper backplate and heatsink must be performing better than my stock backplate with a sandwiched on heatsink.
My fan although only 80mm is a 0.6amp 12 volt high power one mounted straight on the finned aluminum its a noisy bugger, could that be the difference? The Delta 80mm sever fans are 2&3 times the airflow and even noisier
As there are 20 odd ram chips on both sides of the board maybe the highest chip temp is reported and that is on the GPU chip side now?
Maybe some quality thermal pads on the GPU side memory chips would help. 24x7 mining really puts thermal wear & silicon degradation on the cards so much more than 12 hours a week gaming so any temp reduction will exponentially increase card life. A 3 year gaming card life becomes 2-3 months mining

 

[Nelly]

Thermal camera of PNY 3090 backplate mining ethereum

The heatsink and fan took the RAM chips from 86 Degrees to 68 Degrees
Just need another High power 80mm fan to cover the left of the heatsink and knock down the 36 degree peak

 

[TransAmDan]

Thats imprssve to see this on a thermal imaging camera. Thanks for posting. Have you had a chance to try the 120mm fan?

 

[Nelly]

Yes the 120mm was not enough flow so it was worse I need a High power 120mm or i will get another ex-server Hi power 80mm and centralise them across the heatsink. The thermal camera does show the RAM chips hiding behind the backplate really well

 

[Nelly]

Finally got the High power Delta Server fan 10 Watts and fast enough to take your finger off
Maximum heatsink Temp now 29 Degrees but Ram Temps exactly the same (2 Degrees higher but my garage is now 2 Degrees higher ambient).
Comes down to my previous thoughts and the same demonstrated with Dans setup, the Ram temp is the highest of all 24 chips and that is now one of the 12 on the GPU side. The backplate cooling of the 12 rear mounted Ram chips is not the issue now.

 

[TransAmDan]

Wow, that is some fan there, what RPM does that go at?
Great to see more photos and your progress.

I've not made my other two modifications yet. so still have 2 x unmodified 3090's running at 115mh/s to keep temps below 100deg C. I do plan on starting making the heatsinks for them this week. When I attached these heatsinks I plan on repasting the GPU and adding better heat transfer compound to the ram chips.

 

[Nelly]

It is 3500 rpm and 120CFM but its a high pressure fan so it can push air through the channels of the heatsink without the flow dropping off a cliff

 

[TransAmDan]

Whipped up a drawing of the heatsink. This is viewed from the outside, viewing through it, showing where the copper pads are placed. the grey box is the 100x100mm heatsink stuck on the outside in hope to draw as much heat as possible away from the RAM chips.

 

[TransAmDan]

Backplate shapes cut out, holed drilled and countersunk.

Also cut out the strips for the raised parts that sit over the IC' Had to use a hacksaw in the end, as a jigsaw wasn't great at stright lines. Still need to but these strips to length.