Thanks for the temps guys. It definitely gives me a better idea for what's going on. Those optimus temps are nice!
 
I'll try changing out the backplate pads with the blue ones when I adjust those screws this weekend. I can't get to them without taking the back plate off so I might as well see if there's a temp difference with using them opposed to the stock ones. It'll be interesting to see if loosening the pcb/acrylic screws effects the pressure across the waterblock and if temps change as a result.

buttabean
What is memory junction temp? I just loaded up hwinfo and I'm getting 90c so there's definitely something not correct
 

I wouldn't doubt it at all if your back VRAM is hitting 90c. That mem gets hot and the stock backplate is not good.

Buttabean, You have something wrong going on with yours.

Mining 23 hours a day I am peaking at 74*C without a backplate at all. Same block as you.
 
https://forums.evga.com/3...back-Mod-m3221639.aspx

buttabean, thanks for the great detailed posts. I've awarded you two BR's for the two most informative/in depth posts. 

Some more testing with stuff i had laying around.
 
 
These were some copper vram heatsinks with thermal tape preapplied. With a 80mm fan I was previously using, it yielded the same results as the stock backplate. Pay no attention to my poorly printed legs
 

 
I also propped a 120mm fan onto some large heat sinks just to see if the fan size would change things. Unfortunately due to the height of the heatsinks, it moved the fan too far away which then caused temps to rise.
 

 
I then tried the backplate with the leftover thermal tape that came with the kit. I would not recommend doing this due to screw heights on the waterblock. The screws hit the backplate which then prevents proper pressure. I saw temps hit 100C with memory junction temps
 
At this point I decided to lower the gpu to the second pci-e 16x slow to see if having the card close to the mb memory was effecting things, and also allowed more room to work with the back memory. Nothing changed.
 
Last ditch effort, I remembered I bought some heatsinks that were way too long to be used for m2 drives. I located them, cut them to size with a hacksaw. 
 

 
Using the supplied thermal pads that came with the heatsinks and the 80mm fan, i'm getting around 88c. I need to upgrade the fan and go from there. The heatsinks are quite hot to the touch so the thermal pads are working. I'm sure some mx4 or thermal grizzly would work a lot better. The fans the weakest link I think at this point. I'll try the 92mm noctura fan later today.
 

 
 
Obviously those high spikes are not happening. 400C  Getting good averages though and I haven't seen the gpu2 and memory rise any higher than those "current" readings.
 
 
I have a few ideas I want to explore from this point.
 
One involves 3d printing a backplate with cutouts for the heatsinks and fan which I started doing already.
 
The other is, I ordered a square copper plate that i was thinking of using as a base to attach a preexisting threadripper waterblock to. Thinking if I taped off where the memory modules are, then spraying the base with plastidip or liquid tape, and then used thermal paste on the taped off spots.  Then attach the waterblock to the 3d printed backplate. I'm thinking this would be overkill lol
 

Razgriz2006

buttabean
Some more testing with stuff i had laying around.
 
 
These were some copper vram heatsinks with thermal tape preapplied. With a 80mm fan I was previously using, it yielded the same results as the stock backplate. Pay no attention to my poorly printed legs
 

 
I also propped a 120mm fan onto some large heat sinks just to see if the fan size would change things. Unfortunately due to the height of the heatsinks, it moved the fan too far away which then caused temps to rise.
 

 
I then tried the backplate with the leftover thermal tape that came with the kit. I would not recommend doing this due to screw heights on the waterblock. The screws hit the backplate which then prevents proper pressure. I saw temps hit 100C with memory junction temps
 
At this point I decided to lower the gpu to the second pci-e 16x slow to see if having the card close to the mb memory was effecting things, and also allowed more room to work with the back memory. Nothing changed.
 
Last ditch effort, I remembered I bought some heatsinks that were way too long to be used for m2 drives. I located them, cut them to size with a hacksaw. 
 

 
Using the supplied thermal pads that came with the heatsinks and the 80mm fan, i'm getting around 88c. I need to upgrade the fan and go from there. The heatsinks are quite hot to the touch so the thermal pads are working. I'm sure some mx4 or thermal grizzly would work a lot better. The fans the weakest link I think at this point. I'll try the 92mm noctura fan later today.
 

 
 
Obviously those high spikes are not happening. 400C  Getting good averages though and I haven't seen the gpu2 and memory rise any higher than those "current" readings.
 
 
I have a few ideas I want to explore from this point.
 
One involves 3d printing a backplate with cutouts for the heatsinks and fan which I started doing already.
 
The other is, I ordered a square copper plate that i was thinking of using as a base to attach a preexisting threadripper waterblock to. Thinking if I taped off where the memory modules are, then spraying the base with plastidip or liquid tape, and then used thermal paste on the taped off spots.  Then attach the waterblock to the 3d printed backplate. I'm thinking this would be overkill lol
 

Why not a thread ripper block directly on the back ram with paste and then use 3mm ultra soft pads on the back of the die?

Custom fabbing the mounting brackets would be a challenge.

The simple answer is to buy the EK nickel block and Be done with it. It sucks that option is not available right now.

EK's active water cooled backplate should be released soon.

I haven't put much into this other than stuff i had already. The fans I can always reuse for other projects.  So I put the 92mm fan on and I didn't really notice a difference in air flow. I have a slim 120mm i'm going to try and I am going to switch out the thermal pads with mx4 once I make a cut out bracket so I know the heatsinks cant move around. Nothings screwed down yet since i'm still prototyping.
 

 
 

Dabadger84

phroze
EK's active water cooled backplate should be released soon.

Wonder if it'll fit a Kingpin, I wouldn't mind trying it out & adding it to my loop (temporarily) wouldn't be that hard.
 
I got another rather uh... large... set if heatsinks & some different thermal pads incoming.  The expenditure in to this experiment is growing, but I'm determined to get my temps where I want them, without taking the card's face-side apart to redo those pads as well (because I'm extremely paranoid I'll mess something up if I do lol)
 
Got some 12.8 W/mK thermal pads incoming, I'm going to use those on the VRAM areas for the heatsinks, then if I have enough left, from the backplate to the chips themselves, then use the Ayunni everywhere else.
Basically my card is going to no longer be vertically mountable, because the thermal pads don't really "stick" the heatsinks to the backplate very much... but I do believe once I get everything the way I eventually want it, with no thermal tape, thin pads on the backplate side of things to the heatsinks... we'll see.  I also ordered more thermal tape in case I decide to revert things at some point soon, which I might.  I gotta stop putting more in to this though, between the new heatsinks I have coming, the new thermal pads, and what I've already bought, I've spent almost $200 now :-D

Yeah things can definitely balloon fast. One of the reasons I'm reporting my findings so others don't go crazy wasting money. I only spent 30 bucks on fans. Rest of the stuffs been sitting in draws for years. 
 

Razgriz2006
I tested 140mm Noctua industrial vs 120MM Noctua industrial last night.
 
The 120mm aligns better, but performs worse than the 140mm. My guess is even with the 140mm being too big there is no substitute for the raw amount of CFM difference between the two.

hmm I think you're right. Need more cfm to cool the heatsinks faster. I was looking at gpu blocks last night, I came across this https://www.performance-pcs.com/water-cooling/water-blocks/water-blocks-vga/watercool-heatkiller-gpu-x-6850-for-ati-reference-design-6850-water-block-wc-15005-d.html tempting to buy it  since it's only 50 bucks and use some copper shims to raise over anything that it could touch other than the vram, then 3d print a backplate to attach it to the card.  It's too heavy. 
 
 

Razgriz2006

buttabean

Razgriz2006
I tested 140mm Noctua industrial vs 120MM Noctua industrial last night.
 
The 120mm aligns better, but performs worse than the 140mm. My guess is even with the 140mm being too big there is no substitute for the raw amount of CFM difference between the two.

hmm I think you're right. Need more cfm to cool the heatsinks faster. I was looking at gpu blocks last night, I came across this https://www.performance-pcs.com/water-cooling/water-blocks/water-blocks-vga/watercool-heatkiller-gpu-x-6850-for-ati-reference-design-6850-water-block-wc-15005-d.html tempting to buy it  since it's only 50 bucks and use some copper shims to raise over anything that it could touch other than the vram, then 3d print a backplate to attach it to the card.  It's too heavy. 
 
 

Real bummer that the TR4 blocks wont work...
 
https://www.overclock.net/threads/heatkiller%C2%AE-gpu-x%C2%B2-6850.1326365/ Maybe i dont have the right imagination but looking at those pics im not sure the angles on that block would work??? Radeon 6850 block right?

oh i was looking for a back shot, couldn't find one. I would use copper shims.
https://www.performance-pcs.com/water-cooling/water-blocks/water-blocks-vga/bitspower-gpu-block-for-ati-4870-lightweight-version-shiny-silver-bp-wbvga4870l-sl-d.html
this actually looks to be almost perfect. My only fear is the cooling may not be adequate from the looks of the review. I'm tempted at that price. I've got rewards so it would be free lol. Only problem i see is others trying to find this cooler if it does work.

Dabadger84
Got some new heatsinks (40 x 40 x 11) incoming, with some double sided adhesive pads & thermal tape, I'm just gonna go full ham & do the entire area of the back of the card that has heat producing elements... so from before the output port side VRM all the way past the power-plug side VRM.  Should have more than enough to do that with these incoming:
 
https://smile.amazon.com/gp/product/B07YWL7DFS/ Between those & what I already have, doing the entire backplate wouldn't be a problem... but there's not much of a point in continuing the heatsinks past a certain point on the far end of the card, there's nothing there to dissipate.

Those look nice. My problem I had when I was applying my heatsinks were the screws near the edges of the memory. This required me to cut them to size or they wouldn't sit right. It might be different for you and the hybrid kit though... Maybe drill holes into the
 
4 heat sinks that emconpress the edges? The memory modules are 14mm give or take in . Ideally, if you could find a 85mm square heatsink, it would lay across all the vram but those darn screws would need to be cut out.
 
I was talking to Razgriz2006 via pm. Raz convinced me to pickup a ekwb backplate and I'm going to mod it. I bought some copper shims
 
https://smile.amazon.com/gp/product/B00OUGX47Q/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1
https://smile.amazon.com/gp/product/B07XW9FBDN/ref=ppx_yo_dt_b_asin_title_o01_s01?ie=UTF8&psc=1
mx-4 paste them so they're not conductive if they move around while sandwiching and will improve heat transfer. Then I'm going to plop my ekwb threadripper waterblock on the back. if it works, I'll add threads to the backplate for permanent install.
 
 

They go for nothing on ebay

Dash8Q4
I have the same waterblock and it's awesome. Better instructions would have been good haha. Now with regards to the memory junction temp, what is the maximum operating range?
I'm using the stock backplate and while my gpu/mem/pwer temps are reasonable 40-50s, the memory junction is up in the 80s. I read in another forum that according to nvidia, 100 and above is still normal for memory junction(this was regarding a founders edition card).
I might end up getting those passive heatsinks since mine is vertical and I can just leave the backplate off, nothing can be seen in the back.
 

It's the max internal memory temperature. It'll start to throttle at 110C Normally I would say just slap a fan on the backplate and be done with it if you don't mine, but it seems that mining stresses the memory significantly beyond any other process. I see 62C for folding and other applications.
 
My brother has a founders card, we noticed that his was not mining no where near as good as the ftw when I got mine. When he dropped a waterblock on it, it stopped throttling. That's scary that there were no reading for this memory temperature at first. Even with 100% fan it was throttling. Could you imagine if they didn't add that to hwinfo. There would be a lot of dead cards lol.

Razgriz2006
I really like that heatsink you found as a cheaper solution.

Mining definitely takes the temperatures to another level. As far as whats "normal" we wont know whats good or whats really "bad" until all of our cards get more and more thermal cycles and parts start failing.
My objective is to get to Sub 70°C (TJ Max) mining with a normal house temperature. After that, lower is better because you can clock higher and get better Port Royal scores.
 
Some of you folks may hate mining, but Ive banked $485.59 since ive started doing this in January. Its a great way to offset the huge increase from going 2080 ti to 3090.
 
 

indeed. I ordered one. Found a ebay seller in NY so hopefully it gets here before I go down the waterblock hole lol.
 
I think what I might do is plop it on the appropriate amount of shims that the backplate would need, then test temps with and without a fan. then put the ek backplate on, plop the heatsink on the back of it and test again. Then move on to a water block. This way I don't have to keep tearing things apart. Hopefully I can share the results by this weekend.

Razgriz2006

buttabean

Razgriz2006
I really like that heatsink you found as a cheaper solution.

Mining definitely takes the temperatures to another level. As far as whats "normal" we wont know whats good or whats really "bad" until all of our cards get more and more thermal cycles and parts start failing.
My objective is to get to Sub 70°C (TJ Max) mining with a normal house temperature. After that, lower is better because you can clock higher and get better Port Royal scores.
 
Some of you folks may hate mining, but Ive banked $485.59 since ive started doing this in January. Its a great way to offset the huge increase from going 2080 ti to 3090.
 
 

indeed. I ordered one. Found a ebay seller in NY so hopefully it gets here before I go down the waterblock hole lol.
 

I ordered this one: I will also report findings but for $10 shipped it was a steal. Dont worry I bought a GPU support bracket so it wont be too heavy.
https://www.ebay.com/itm/...p2334524.c100667.m2042

hmm not sure it'll work but maybe? it says 3" in one length so that's 76mm. really need 85mm which I believe is 3.35".
 
I wish I did some more digging. I found a heatpipe heatsink that's 90mm square.  https://www.ebay.com/itm/Supermicro-2U-SNK-P0038P-LGA1366-X8-Intel-Xeon-Socket-Heatsink/193765784953?hash=item2d1d573d79:g:f4oAAOSwHpZfvYgf
 
https://www.supermicro.com/en/support/resources/heatsink
SNK-P0048P