GX640 Cooling Mods?

Remember: Furmark gives you the memIO-value! All the sensors are inside the gpu die. There is no vram temperature.
So, I never would replace the vram-pads with paste only, because of the gap. You don't know if your memory is burning and getting damaged.

And you have to compare same furmark settings. 800x600 windowed runs cooler than 1680x1050 fullscreen!

 

That's a good point @tilla. I've been trying to warn people here on using paste on the ram but nobody seems to listen. Paste is designed for metal to metal heat transfer, not metal to plastic. Also, once the paste gets heated it starts melting and flowing, thus getting thinner than the actual layer that was applied (if you use a conductive paste, then things get even worse as you can imagine). Also, paste can permanently stain the ram chips because their surface seems to absorb the paste like a sponge. I don't see why people are not just using thinner thermal pads to compensate for the gap between the heatsink and GPU. MSI did that with the newer 640 models.

 

haha, heatsink modding went well. i had a old nvidia card with a small heatsink lying around, and with some cutting of this thing i got some neat results. now i think i will read up on how to undervolt. anyone know any good guides? as its the first time i open a pc at all with this laptop i feel i am learning a lot, a bit clumsy, but it is fun now i idle @ 43 celcius with backpanel of, and 45 with it on

 

Can you post some pics ?

 

If you upgrade to 10.11 drivers you can see lower idle temps.

On my 740 I idle at about 41C instead of 44-45 like before. (no mods)

 

and besides good idle temps, is there any downsides to 10.11?

 

holy those were huge as **** sorry

man i did not see what a huge mess i made with the cooling paste until i saw those pics.
any reason to take some away? i used a hansom amount on the vram to be sure, and so its splatted all over now;D

 

Duuuuuuuuuuude those pics are nasty because I have trypophobia......

 

good thing its not your back panel then. and that it wil be hidden almost all the time

also, i have added more holes along the (heat pipe?) now. hopefully that will lower the temps further.

sorry, but it is for the greater good. will not post any other pics of it tho. for your sake

also i updated the driver to 10.11 i don't know what i had before, but 10.11 had negative effect onn idle temps at least. now i idle @ 46 with no back pannel:/ hopefully boosted stability and preformance makes it worth it.

edit*
seems 10.11 had improvements compared to the older 10.10, so ill be sticking with 10.11 for now

 

oh so much i have learned.



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http://img109.imageshack.us/i/skjermbilde.jpg/

room temp: 20,5 c
surface it stands on: steel rist(those you use in the oven usually)
redid the heatsink mod and blowed the cooler clean with a compressor(there was a lot of dust that did not come out when using canned air)

 

so, is it safe to remove the heatpads from the gpu ram? are they useless?

 

It is possible to go without completely.

My theory is you need to use a thick paste for the vRAM and a thin one for the core. Maybe even bend it a little.
Most people prefer to use copper shims about .5mm, and that will help the temp more than nothing.

 

I tried 1mm pads but they are about the same as the stock ones, temp wise. I then tried 0.5mm pads and they cut the temps in half both on the cpu & gpu.

before idles cpu 56 / gpu 58
after idles cpu 43-44 / gpu 42-44