6990M and memory heat

So far, I've been able to achieve a stable OC of 820/900 on my 6990M which runs around 80-82C @ full load. However, when trying to bring up the memory to 1000, it gets pretty hot...around 88-92c. I'm going to assume that this could be a result of mediocre thermal pads on the memory modules. Thus, I am wanting to try some of these Premium Thermal Pads | Page 1 | Sort By: Product Title A-Z - FrozenCPU.com   but not sure what size/thickness to get. Perhaps someone else on here has replaced the thermal pads and can advise on size and results?

 

A common misconception is the MEM(IO) heat relates to the VRAM but it does not.

The MEM(IO) relates to the controllers located in the DIE and not the thermal pads over the VRAM and caps etc.

Your temps are not much different to mine when I am running at 825/1125 which is stable for me at the moment. My MEM and Shaders can easily hit 93oC under some serious load and I have done substantial testing with different compounds and it comes down it being a mighty powerful card with a large bus and high clocks with mobile cooling, 93oC is not that hot when you think about the output. 110oC is TJ for mobile cards so 20oC below is acceptable for a high end card.

Several have posted results of the memory overclocks and due it being able to run at the same bandwidth when clocked to 1000mhz as a desktop 5870 you dont really need to overclock the memory, up the core slightly and the temps are not effected as much.

 

do u know where the controller on die is?for memory..

 

You answered your own question. The die is where they're located. The die is the big piece of silicon that the heatsink sits on (and that you apply the paste to).

 

Differs from DIE to DIE on my 5870M they were located at the north end of the chip at the edge. It is important for the compound to evenly spread over the entire DIE for this very reason, not too much but not too little.

End of the day it does run hot. low 80's at stock but as soon as you raise the memory clocks expect 90's under heavy constant load for the MEM(IO) and Shaders.

 

Thanks Yiddo! That actually makes perfect sense. It takes some serious load to get the temps to hit 90+C....Rift puts it through it's paces.

 

is there any way to spot it with bare eye??

 

No. Here is an image showing the IMC on an i7 sandy bridge. (right hand side, bottom is the pipeline to/from RAM)) http://regmedia.co.uk/2011/11/14/core_i7_sandy_bridge_die_large.jpg
Since our notebook CPU's and GPU's do not have heatspreaders, we see the actual silicone of the chip, however we cannot see the transistors within the chips (which is where the IMC is).

 

nice man!thx for the info!!can u run a vantage test for only the first 2 tests for the gpu and post ur temps?thx again +rep!!

edit:also the black tape around the die what is it?what use it has??

 

sure! thanks for the rep
*edit*
After running tests 1 and 2, the GPU temp topped out at 84c @ 820/900 clock settings.
The black film around the chip is there to protect the resistors from coming in contact with potentially conductive thermal paste, and/or the heatsink itself.

 

my 6970m doesnt have this black firm around die but i use ic diamond 7 and never have a prob!!!

 

Not sure why they put them on the 6990M's...this is actually the first Radeon I've ever owned and chose it as my GPU over the 580M due to the price difference. Also, IC diamond is not electrically conductive, so you shouldn't have any problems either way. I personally use Noctua's NT-H1 which I applied myself to save money vs. having my reseller apply IC Diamond.

 

I think it is more to keep the chip clean and prevent damage by scraping off a thick TIM should it overflow off the chip, the majority of compounds these days should be non conductive and it would be silly to use a conductive one with the price of hardware at the moment.

ICD is a fantastic TIM but I hate the way it stains the copper.

 

thats true for icd 7 that stains the copper after some months...i read that Prolimatech PK-1 is a very good paste.how it compares with icd 7??

 

Some bloke recommended it to me on here and I tried it and I have never gone back. For a thin compound its results are outstanding but it does need replacing on a yearly basis so for a Clevo/Sager its fine for ease of access.

The problem was finding it in the UK was a pain elsewhere I am sure it will be fine and it came with a good 5 grams so plenty to keep me going.

If you are in other parts of the world however the one compound I want to try but cannot get it here is Indigo Xtreme, if you can get your hands on it forget the rest.

 

so u used both pk-1 and icd 7??what's the difference between them?

edit:what method u used to apply them?

 

I have used numerous type of compound but ICD and PK1 my favorite.

ICD is a great compound for cooling and preventing higher temps on the downside it will causes temp to drop slower from my experience once the load has been removed and of course the staining problems. Its ease to apply (the pea or blob method) makes it a perfect TIM for beginners just apply a blob and reseat the heatsink. I switched because its inability to drop my idle temps low enough to switch the fans off fully.

PK1 gives me the best temps idle and load, it does not stain and comes in much more quantity however the application is key with it, I refuse to do the credit card method because of bubbles forming so a perfect thick line I find works best. Simply when you apply it move your hand slowly across the DIE so that the compound forms thickly and will reach the edges.

 

do u have some test comparisons with numbers??(idle and full load)when u said a thick line what u mean??i have the 6970m so it has the same die size as 6990.also u said move ur hand slowly across the die,u mean with the heatsink sitting on??sorry my friend but im from greece and dont know very good english...very big thx for ur hep and ur time!!!

edit:here some screenshots shots with full vantage run!!also gpu and cpu idle temps!!room temp is 21 celsious.

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The difference in compound is going to be minimal really people argue certain compounds are better and achieve lower temps and this is sometimes true but IMO it is not marginal enough for me to care. 72oC is no different to 75oC personally because the hardware will outlive my patience with its ability to perform

I just focus on the application of the compound and my testing is focused solely on achieving the best temps overall from application. I find PK1 works best for me with my method of applying the compound, I have tried ICD and as mentioned the staining annoys me and I had to do some serious cleaning to sort out the mess it left behind but as a compound it is excellent.

When I said move your hand slowly I meant when squeezing out the compound that was all because PK1 comes out thinly and the slower you apply it the thicker the line will become.

 

as u saw at my screenshots i think my temps are amazing for now.what u say??im little skeptic to try pk-1 at least for now!!

 

Sorry my work computer will not show images

I just checked on my mobile and yes those are spot on you need not worry.

Stick with what works best for you I only switched from ICD because of the staining problem with my G73JH it had such a poor heatsink and clearance from the DIE ICD was the only compound that made a real difference because it was so thick.