New 7950 - what chips do I need to cool

[The Von Matrices]

Hi everyone,

I just bought and received two ASUS AMD Radeon HD 7950 DirectCU II. I plan to use it for my water cooling system with my MCW82 blocks. I already have the adapters for the cores, but I know I need to cool more than the core, so I bought some aluminum heatsinks with thermal tape. I know I need to put them on the VRM chips and the memory, and I know which chips are the memory modules, but could someone help me by pointing out all the VRM chips that I need to put a heatsink on? I have taken pictures of the naked card and posted it below. Thanks!

[TRWOV]

Everything marked with a Q is a regulator (in this case the little chips between the two capacitor columns, Q541, Q543, etc.). Inductors (L) will also benefit from cooling (they are close to the power connectors).

[The Von Matrices]

Here's the back of the card as well. I don't think there's anything that needs to be cooled though.

[mediasorcerer]

What a good score, great looking cards if you dont mind me exclaming.

[The Von Matrices]

Originally Posted by mediasorcerer

What a good score, great looking cards if you dont mind me exclaming.

I was amazed myself; snagged them up lightly used for $500 shipped through eBay. And they work great; no issues at all.

[eidairaman1]

i know this might be riduculous but wouldnt thermal epoxy mixed with thermal compound work better for heat transfer for ram/VRMs than thermal tape?

also as an optional solution put a fan on the back of the card, i mean it dont have to be a fast and loud unit, but it would help with cooling air to the PCB itself (PCBs act as heat spreaders too just not as well as metal is) 60-80 mm would work well

[largon]

Originally Posted by TRWOV

[...] Inductors (L) will also benefit from cooling (they are close to the power connectors).

Those are 12V input inductors, they don't need any cooling. Even the vGPU power inductors marked "R22" don't need to be sinked, light air flow is good enough.

Here, sink these:

[mediasorcerer]

Originally Posted by eidairaman1

i know this might be riduculous but wouldnt thermal epoxy mixed with thermal compound work better for heat transfer for ram/VRMs than thermal tape?

also as an optional solution put a fan on the back of the card, i mean it dont have to be a fast and loud unit, but it would help with cooling air to the PCB itself (PCBs act as heat spreaders too just not as well as metal is) 60-80 mm would work well

Actually, i've tried this, and it makes a big difference, quite a bit of heat comes off the back of the chip, helping to remove that drops temps on my card by 5-8c no joke already.

[eidairaman1]

Originally Posted by largon

Those are 12V input inductors, they don't need any cooling. Even the vGPU power inductors marked "R22" don't need to be sinked, light air flow is good enough.

Here, sink these:
http://img.techpowerup.org/121019/card2-marked.jpg

may not but id still sink them anyway

[Derek12]

Originally Posted by largon

Those are 12V input inductors, they don't need any cooling. Even the vGPU power inductors marked "R22" don't need to be sinked, light air flow is good enough.

Here, sink these:
http://img.techpowerup.org/121019/card2-marked.jpg

Inductors can also heat considerably. I had boards with the inductors so hot you couldn't touch them. Even some which they were discolored & brittle due to heat. Though I suppose newer ones are more efficient.

[largon]

Temperetures are likely due to conduction from associated regulators.

[SonDa5]

I'd go with what Largon has marked and if you plan on over volting ram and over clocking heat sinks on ram wouldn't hurt as well. Make sure you hit the marks that Largon marked, all important hot VRM components.

[james888]

Originally Posted by mediasorcerer

Actually, i've tried this, and it makes a big difference, quite a bit of heat comes off the back of the chip, helping to remove that drops temps on my card by 5-8c no joke already.

How did you attach it?

[The Von Matrices]

Okay, I've finally applied the heatsinks and got my system running. The biggest challenge was actually one I never anticipated. I needed to cut the PCI slot bracket from 3 slots to 2 slots wide so that I could fit the two cards in my case. Fortunately, a rotary tool did the job.

I ended up putting heatsinks on the RAM and the VRMs. The inductors don't have heatsinks. My case is a Nine Hundred Two, so a low-speed side fan blows on the cards providing some cooling as well. Interestingly, the hottest components on the card seem to be the memory modules, something I did not expect. They even seem hotter than the VRMs. I value silence over extreme speed, so I don't really plan to overclock the GPUs. Because of this I don't think the lack of cooling on the inductors will be a problem.

In regards to eidairaman1's post about using thermal epoxy, I actually have used it on other cards in the past, but I didn't find the cooling performance significantly better than thermal tape. I also am looking toward the future, when I eventually upgrade again, and I want to be able to reinstall the standard heatsink. The standard heatsink's heatpipes barely clear the memory modules and leave no room for heatsinks on them, which means that I will have to remove at least the memory heatsinks before selling the card. Doing this with thermal epoxy is a problem, although I may consider using it for the VRMs and the inductors if the cooling performance is inadequate.

I will try to get a picture of the cards with the heatsinks on them, but right now they are in the middle of the water cooling loop and are relatively difficult to take out to photograph. In hindsight, I should have taken a picture before installing them.

Thanks everyone for the help.

[Jack1n]

You can most likely OC those cards to 1000/1375 on stock volts increasing temps by only a bit and increase performance significantly,ive also been able to run 950/1375 while undervolted to 982Mv

[The Von Matrices]

Running at stock settings, the core temps max out around 48°C. It seems high for water cooling, but remember that I am using an adapter plate so there are actually two layers of thermal grease, so I think they are OK. The VRMs max out around 60°C, which seems safe to me, but can anyone verify this?

[SonDa5]

Originally Posted by The Von Matrices

Running at stock settings, the core temps max out around 48°C. It seems high for water cooling, but remember that I am using an adapter plate so there are actually two layers of thermal grease, so I think they are OK. The VRMs max out around 60°C, which seems safe to me, but can anyone verify this?

Temps look decent.

[Derek12]

Originally Posted by largon

Temperetures are likely due to conduction from associated regulators.

No no they were way hotter than the nearest MOSFETs.

[The Von Matrices]

I've noticed an issue with my system now that I've been using it a few days. When using anything graphically intensive (so far I've tried Furmark, Unigine Heaven, Left 4 Dead 2, and Starcraft II) the system randomly locks up well after starting the game. It's not a BSOD; it's a complete freeze of the content on screen that needs the power button to be held in order to resolve. I'm stuck in determining what is causing it. I'm left with 3 options: a cooling issue, a issue with Windows 8/AMD's drivers, or a flaw in the cards. I would normally just say it's a software issue and wait for the next driver release to occur, but I don't want the return period to expire on my cards if they are the problem. Does anyone have any suggestions on how I can diagnose or fix this?

[eidairaman1]

Originally Posted by The Von Matrices

I've noticed an issue with my system now that I've been using it a few days. When using anything graphically intensive (so far I've tried Furmark, Unigine Heaven, Left 4 Dead 2, and Starcraft II) the system randomly locks up well after starting the game. It's not a BSOD; it's a complete freeze of the content on screen that needs the power button to be held in order to resolve. I'm stuck in determining what is causing it. I'm left with 3 options: a cooling issue, a issue with Windows 8/AMD's drivers, or a flaw in the cards. I would normally just say it's a software issue and wait for the next driver release to occur, but I don't want the return period to expire on my cards if they are the problem. Does anyone have any suggestions on how I can diagnose or fix this?

with windows 8 being so new it could be an issue

[largon]

What kind of heatsinks did you use for the VRMs?

[The Von Matrices]

Originally Posted by largon

What kind of heatsinks did you use for the VRMs?

They are aluminum heatsinks - this product, specifically.

[largon]

IMO, way too small heatsinks, and thermal tape is so-so.

edit:
Grab a hacksaw and carve into some surplus heatsinks and you'll end up with something like this:

[james888]

Originally Posted by largon

IMO, way too small heatsinks, and thermal tape is so-so.

edit:
Grab a hacksaw and carve into some surplus heatsinks and you'll end up with something like this:
http://img.techpowerup.org/121021/la...m-vrm-sink.jpg

what did that come off of

[eidairaman1]

Originally Posted by james888

what did that come off of

looks like a SLot 1 heatsink honestly