Cooling the backside of a GPU?

[tkgclimb]

Hey I was just wondering,

In an ATX case the backside of the GPU is facing up (part with all the silicon and sodder marks).

Any way this back part is hot like the rest of the card, and I was wondering if there would be any way to cool it. So you would have cooling on both sides of the card.

There is one major problem though, you cant put metal heatsinks on it because you could (would) short out the card.

Any thoughts.

 

[masterjaw]

Get a fan and blow air into it.

 

[tkgclimb]

yeah thats about the best I think I can do is a fan blowing on to it. And there really is now reason why I want to, just was curious if anybody had done anything before or heard about anything before, (that was a little better than just a fan) and it would lower your temps which is good.

 

[masterjaw]

Install an aftermarket cooler? Would break the warranty though, if you have one.

 

[tkgclimb]

Install an aftermarket cooler? Would break the warranty though, if you have one.

Yeah, but they are just like a good stock cooler, they don't cool the back of the GPU,

And it's not like my temps are bad. I'm just curious.

 

[amnotanoobie]

I think that there really isn't a big benefit from cooling the underside (or topside, depending on where you are looking at), since usually most of the heat would be much more attracted to the big hunk of metal attached to the other side.

Anyway I think the trouble is the small transistors/resistors/thingies are sticking up and it is really hard to cool a non-flat surface. Unless of course if you create a heatsink that has etches to account for those and fit exactly on the backside of your gpu.

 

[tkgclimb]

I think that there really isn't a big benefit from cooling the underside (or topside, depending on where you are looking at), since usually most of the heat would be much more attracted to the big hunk of metal attached to the other side.

Anyway I think the trouble is the small transistors/resistors/thingies are sticking up and it is really hard to cool a non-flat surface. Unless of course if you create a heatsink that has etches to account for those and fit exactly on the backside of your gpu.

exactly the problem, and yes it wouldn't have as much benefit as the main cooler, but if you've ever felt while its running, it's hot, at least a lot hotter than ram, which they make heatsinks for

 

[ram1009]

stick this pointed at the back side

http://www.bestbuy.com/site/olspage.jsp?skuId=8013339&type=product&id=1156203596895

...but why would want to ?

Your ignorance is showing. Obviously you've never bothered to feel the backside of a high powered GPU card under load. They get very hot even though most of the heat goes to the heatsink on the other side. The board could be designed to clear an area from the backside in order to attach a heatsink. It might require an additional circuitry layer in the manufacturing process which would increase the cost somewhat. From a purely engineering viewpoint it would be worth the extra cost but the major benefit would be to increase the lifespan of a product which is technologically obsolete before it's even available on the open market. There have been a few attempts at this, I still own one and it's been running fine for many years. I'd be surprised to see any in the future.

 

[swifty_morgan]

I don't remember what they go by ( reverse atx cases ) where the video card would sit the way you would think they should so the heat sink system would work to it's nth........... and then came along the heat pipe system and put a stop to that.
( that's the heat pipe system on mother boards for you slower folks )

 

[RazberyBandit]

^ someone a bit grouchy today?

While GPUs can't be cooled via heatsink on the backside, some cards have double-sided memory chips which can have heatsinks mounted on them. These little copper sinks from Enzotech work very well on such cards.

 

[tkgclimb]

In case your confused I'm talking about cooling the backside in addition to cooling the regular side. I did a little expierment with an 80mm fan that pushes 42 cfm. I pointed it at a 45 degree angle at the back of the GPU on the very end of the GPU. I removed the two PCI slot covers above the GPU, and did some tests here is what I found.

Idle without 80mm fan
61 c
idle with fan
60

Load without fan (GPU fan running at 70%)
71 and climbing (had to increase GPU fan spead to 78 which brought temp to 66)
load with fan (gup fan at 70%)
63/64

So thats a good 8 degrees difference, and thats just with a fan pointing at it, no heatsink. So a heatsink would do good.
Just the fan though doesn't make any sense since my 42cfm can runs at 30dba and makes a lot more noise than just turning up the gpu fan to 80% (well actually not a lot more)

the card by the way is a 9800gtx+ (Idle fan speed is 35%)

 

[RazberyBandit]

Gotta love those slack-ass quiet fan-speed settings in the BIOS for high-performance video cards... LOL. It's honestly one of my biggest pet-peeves when it comes to computer hardware nowadays.

tkgclimb, trust me when I tell ya we hear what you're saying. The problem is, no one designs their cards that way. I'm sure if AMD/ATI or nVIDIA ever design a double-sided GPU, they'll do it. But the backside (topside?) heatsink would have to be super-slim to allow clearance for the above card slot. Yeah, I know, most motherboards don't have a slot above the primary VGA slot, but more and more companies are designing SLI and Crossfire boards which have a PCIe-X1 slot above 'em.

In the now, maybe you can figure out a way to apply an electrically non-conductive thermal interface material that despite being applied thick enough to support a heatsink, wouldn't trap a ton of heat. The problem is, you'd need a layer that would be far thicker than the thickness at which today's TIMs are designed to be used. That goes for thermal tape, too. That said, you could try it, but it could turn out to be a total waste of a good tube of high-quality TIM. Another problem that arises is, how do you affix a heatsink to such a configuration? Do you use a thermal adhesive, configure your own mounting hardware, or just zip-tie it?

Have fun with that

 

[tkgclimb]

^Good point about the cooler having to be super slim, but even just the option of being able to put a heatsink on would suffice, that way if you can't do it you can't but if you can you can. Anyway on my card there are some spots that don't have metal to short out but still get hot, and I might get some small heatsinks (like the ones razbery showed) and put them on there, I put a copper penny on one of the spots today and took it off a 10 seconds later and it was very warm, and thats with no grease. I might do it but it might not be worth it. I should just call up ATI or Nvidia and say, "design your reference cards with the option for backside cooling"

It really wouldn't be that hard, just like an extra thin layer of silicon to cover up all the metal, it would still get hot but you couldn't really short it. And thats just he simplest design I'm sure they could come up with something a lot better.

 

[ram1009]

or you can point it at the front side like every person in world but I'm sure we lack the intelligence of a F-ing idiot like you who thinks cooling the backside is more important then the front side. Go take your stupid opinions and shove them up your ignorant azz loser!

I said nothing about intelligence, however you put yours in serious question by not knowing the difference between intelligence and ignorance. Neither did I say I would cool the back of any board rather than the front. All I said was that the area under a powerful GPU does get hot and that the fact that you don't know it demonstrates your ignorance of the issue. I look forward to hearing you help me make my case with more misquotes and name calling instead of sticking with the issues.

 

[frozenlead]

So if the GPU only benefits from backside cooling under load, and the stock GPU fan is loud at that level anyway, why not mount a fan to the back of the card, and then install a pot on the fan's lead? Just turn it up when you want. You can probably tap the stock fan power on the card too, if you wanted.

No guarantees for safety.

 

[RazberyBandit]

It really wouldn't be that hard, just like an extra thin layer of silicon to cover up all the metal, it would still get hot but you couldn't really short it. And thats just he simplest design I'm sure they could come up with something a lot better.

Well considering that the metal you'd need to cover up is also a layer of solder points, I'm not certain that would work. Once you add another layer, you still have to move the solder points to that layer to actually solder them. In essence, all you'd be doing is making the PCB thicker at that point.

In all honestly, I think it would take a total redesign of how GPUs are mounted on PCBs to make this work without any risk of shorting any contacts or without having to apply a TIM layer so thick it works adversely. GPUs would need to either be designed to include a backside heatspreader, or designed much like a double-sided memory chip. If they did that, I think backside cooling would become commonplace.

I honestly think it's time the major players (whomever they might be...) in PC design got together and came up with an all-new standard for motherboard and component layouts, as well as case design. ATX is old, and ITX basically just removed the slots. There has to be a better way...

 

[chef7734]

Well considering that the metal you'd need to cover up is also a layer of solder points, I'm not certain that would work. Once you add another layer, you still have to move the solder points to that layer to actually solder them. In essence, all you'd be doing is making the PCB thicker at that point.

In all honestly, I think it would take a total redesign of how GPUs are mounted on PCBs to make this work without any risk of shorting any contacts or without having to apply a TIM layer so thick it works adversely. GPUs would need to either be designed to include a backside heatspreader, or designed much like a double-sided memory chip. If they did that, I think backside cooling would become commonplace.

I honestly think it's time the major players (whomever they might be...) in PC design got together and came up with an all-new standard for motherboard and component layouts, as well as case design. ATX is old, and ITX basically just removed the slots. There has to be a better way...

Thy did get together and the outcome was btx and if failed pretty miserably.

 

[tkgclimb]

Well covering it up would just be the simplest way, but if you put some thought and work into it covering it up wouldn't be that hard, they could smooth out the sodder points a bit and make the thin silicon piece have nochtes to fit where they couldn't smooth it out anymore.

I wonder how they make a CPU heatspreader, if they could just make one of those that went on the backside of the GPU it would work.

Also they don't have to make a spot for cooing the whole thing but just where the GPU core is and the memory, the rest could still be all ridgy and have metal points.

 

[tkgclimb]

So if the GPU only benefits from backside cooling under load, and the stock GPU fan is loud at that level anyway, why not mount a fan to the back of the card, and then install a pot on the fan's lead? Just turn it up when you want. You can probably tap the stock fan power on the card too, if you wanted.

No guarantees for safety.

Thats kinda what i did in my test, though the results were good, for me it wasn't enough warrant leaving the fan there, I was just showing how some backside heatsinks would be a great benefit. (probably even at idle)

 

[RazberyBandit]

^ needs coffee again?

chef: BTX was here and gone so fast, I completely forgot about it... LOL
Maybe it's time to try again?

tkg: Imagine the day when your dual-slot VGA card doesn't use the normal slot and the one below it, but the normal slot and the one above it... When that day comes, the solution to the question you've proposed will undoubtedly have been found.

 

[tkgclimb]

tkg: Imagine the day when your dual-slot VGA card doesn't use the normal slot and the one below it, but the normal slot and the one above it... When that day comes, the solution to the question you've proposed will undoubtedly have been found.

What about a triple slot card ehh,

PS how to you close a thread?

 

[RazberyBandit]

You can't really close it. If you had selected "Looking for a specific answer" when you originally posted, you could select a "Best Answer" among the comments made, which might actually close it. But, I've never used that option, so I'm not certain.

And triple-slot? Man... I dunno about that... Giving up 3 device slots for one device seems pretty steep. Though, there are already several aftermarket VGA coolers that already require 3 slots.

 

[tkgclimb]

So you can't close a discussion thread, uhh,
A triple slot card though big might come in handy for someone who doesn't want to do sli or crsfr, and just wants one power full card or only as one pci-e slot. But otherwise it is a big card, I think the slim or big *optional* backside heatsink is the way to go.

 

[tkgclimb]

test with pics is here

http://www.tomshardware.com/forum/253920-29-cooling-backside-with-pics

 

[wh3resmycar]

http://www.hardwarecanucks.com/foru...hermalright-hr-11-backside-cooler-review.html

one google search and away you go.