Heatsinks on GPU Backplate

[PieEater]

I've repasted and repadded my 6800XT and was wondering if anyone has ever stuck some heatsinks on their GPU backplate above the GPU and memory modules where the thermal pads are and if so was there any appreciable difference in temps.

/Edit: The rainforest place has some active and passive backplate coolers, but I can't really find any positive user feedback.

 

[Bubo]

What I've done in the past with passive backplates I've put on as part of a water cooling setup is just put an 80mm fane above the hot areas with some standoff legs to raise it above the plate, it basically just sits on top of the card. I've no before and after temperatures but common sense says it will be doing something, assuming the backplate is actually in contact with the back of the card via heat pads. I have considered adding those copper ram sinks to enhance this even more but never got round to it. If you added the sinks on their own to your card then I think it would be safe to safe there would be some heat transfer, but would defo be enhanced with some local air flow on to the sinks as per the close fan idea. The only thing to consider beyond this is whether the sinks are going to leave any residue on the plate which you either can't get off, or it somehow leaves an indelible mark, and as such might reduce the sell on value.

 

[Rob_B]

Is the backplate actually metal and thermally connected to the board?

 

[PieEater]

What I've done in the past with passive backplates I've put on as part of a water cooling setup is just put an 80mm fane above the hot areas with some standoff legs to raise it above the plate, it basically just sits on top of the card. I've no before and after temperatures but common sense says it will be doing something, assuming the backplate is actually in contact with the back of the card via heat pads. I have considered adding those copper ram sinks to enhance this even more but never got round to it. If you added the sinks on their own to your card then I think it would be safe to safe there would be some heat transfer, but would defo be enhanced with some local air flow on to the sinks as per the close fan idea. The only thing to consider beyond this is whether the sinks are going to leave any residue on the plate which you either can't get off, or it somehow leaves an indelible mark, and as such might reduce the sell on value.

Thanks for the idea, I have a spare 92mm fan and will run some tests, what I don't want to happen though for heated to get blown against the side of the case so it gets recirculated to the main GPU cooler as this will defeat the object, so was thinking a large passive heatsink would be better in this respect.

 

[PieEater]

Is the backplate actually metal and thermally connected to the board?

Yes and yes, the backplate gets pretty toasty during gaming so there is definitely good thermal conductivity to it, I'll put a thermal sensor on it when I run the tests with the fan on top.

 

[Bubo]

How hot does the backplate feel by the way?

edit: nevermind, answered above.

A bare heatsink would work to some extent, but obviously depends how much general air flow there is. A close fan would work wonders though. As I say, if you are going to be using thermal paste I would lay a fairly confidant bet this would leave a tarnish mark on the plate, so be aware of that. An adhesive pad might not leave as much of a mark, but it is still something to be aware of, if it matters to you.

 

[PieEater]

How hot does the backplate feel by the way?

edit: nevermind, answered above.

A bare heatsink would work to some extent, but obviously depends how much general air flow there is. A close fan would work wonders though. As I say, if you are going to be using thermal paste I would lay a fairly confidant bet this would leave a tarnish mark on the plate, so be aware of that. An adhesive pad might not leave as much of a mark, but it is still something to be aware of, if it matters to you.

Thanks - I've just run a quick test and the backplate gets to 55c above the GPU core. If I got a heatsink I was planning on getting a thermal pad to go under it and just putting a dab of adhesive at the corners and in the centre edge with some weight on it so it should stick with good contact and be fairly easy to remove and clean if necessary. Airflow isn't an isssue, I've got 4 140mm intakes and 4 140mm exhausts.

 

[Rob_B]

Thanks for the idea, I have a spare 92mm fan and will run some tests, what I don't want to happen though for heated to get blown against the side of the case so it gets recirculated to the main GPU cooler as this will defeat the object, so was thinking a large passive heatsink would be better in this respect.

More heatsink won't be likely to help that much, you need to remove the heat not just add more mass to absorb it. Eventually, and quite quickly it will become as hot as the backplate and so the temps will stabilise. Ok, maybe it gives your airflow a little more time to remove the heat but I can't imagine it's a big difference.
If you're adding a flat piece of metal (with a few small fins) to a flat piece of metal just how much surface area have you added? Personally I'd go with airflow directed at the backplate if possible, you could test the difference.

 

[Bubo]

thermal pad to go under it and just putting a dab of adhesive at the corners and in the centre edge with some weight on it so it should stick with good contact and be fairly easy to remove and clean if necessary. Airflow isn't an isssue, I've got 4 140mm intakes and 4 140mm exhausts.

Maybe use a square of aluminium tape to be the layer between the backplate and the sink, then you can use thermal paste on the sink to your hearts content. I assume the adhesive on the tape would come off with some acetone when needed. Still going to advocate for a fan on the sink though, it does need to be forced convection close the the sink for this to work to its best. It will certainly look funky though if you are at all bothered about the looks.

 

[Minstadave]

I was planning to do something similar to my 3090FE, my memory hits max temp and the back plate is very hot so was going to stick a heatsink directly to the backplate to add some surface area.