Copper Mod on Acer Aspire 4937G (NVIDIA G105M)

i believe many of u experience gpu reaching near 100 degrees when gaming, causing laptop to jus turn off by itself.

a gd news here..copper shim solve the problem, which means it lower down temp to prevent tat from happening.

received copper shim in my mailbox yesterday.



thickness is 0.044", 1.11mm, 0.1cm (*actual fit thickness is 0.9mm, wan abit more thicker, get 1.0mm)


size is 0.75", 19.05mm, 1.9cm (kind of too big for gpu, becos the seller hav tat size for tat thickness, but nvm, look below)



wat i do next is to use a sand paper(fine one, not rough one), i use 1000cw since i had tat at home. lazy to go out to get more fine one.

do it on a flat surface, sand until like mirror effect.


now proceed to dismantle the whole laptop.


it seems tat the heatsink is too small for tat copper shim, but no need to worry, the surrounding alum is a little lower than tat copper.






using Arctic Cooling MX-2. apply on both cpu, gpu, n on copper shim after placing over gpu.



Stress test results

*Ambient Temperature: 32 degrees

Before copper mod, wit default thermal pad. i immediately stop the test b4 it blackout.



After thermal pad was replaced by Copper Shim.
temperature was still steady at 88 degrees after 11mins!

 

No thermal compound ?

 

The copper shim acts as the thermal interface, and if done well can perform more effectively than compounds.

 

hmmm

I guess the best proof of that would be for someone to apply a micro-thin layer to both sides of the shim. . . . (I do mean micro thin - the aim of thermal compound is to fill the valleys on both sides if the interface while adding little or no distance between the highest peaks. It is not glue or bath sealant, but conducts heat much better than an air gap !)

In theory two mirror-flat surfaces perfectly aligned do not need or benefit from thermal compound. However 1000grit paper does not produce a mirror, and screw down GPU+CPU cooler assemblies do not produce perfect alignment. And with a shim there are two interfaces now compared to one before.

The 1mm size is interesting though . . wow. if the mechanical design (or some mod) creates a gap that big between the cooler and the GPU top when the CPU is down tight then filling 80- 90% % of that gap with Copper shim rather than thermal compound is a good idea (copper is a much better heat conductor) . I cannot see any scientific reason to have a shim otherwise... Many many Laptops do fix the CPU - cooler gap with screws and leave the GPU to take its chances with a thick pad or a non-pressure type thermal compound like akasa pro+ 5022. As there will be variations in the mounting height of the CPU socket and the CPU itself some float somewhere is clearly needed but 1mm sounds like poor engineering practice . . .

So I think these results nicely demonstrate the rubbish performance of thick thermal pads rather than the best cooling that is possible.

Also tempted to ask if any compound was (re?) applied to the CPU as that is not remarked on either !

 

thread updated!

yes, i do apply thermal compound to both side of copper shim.

and also, after taking some time to look at the heatsink, it seems that the heatsink is not completely flat.

 

Cool (sorry couldn't resist that)

The whole idea of 1 cooler on two separate flat topped chips is crazy but the thermal compound usually manages to bridge the gap and make it all work.
There are some lovely stories of 'another' make of laptops where the gap from cooler to GPU is big enough to insert a coin! No surprise when some of these fail after a while

 

This is nice, I've tried and success...

can play dirt2 with medium smoothly without shutting down...

but still need cooler pad below it..

 

Could anyone tell me if it would be a good idea to do this on my Aspire 7520 Northbridge (GPU)?

If so, what size would I need?

 

no point doing it on northbridge..

 

IC7 compound is claimed to have thermal conductivity of 2000-2500W/mK which is ~5x better compared to pure copper 406W/mK. Why then have a copper shim in between to create more transitional losses?
Innovation Cooling 7 Diamond CPU Thermal Paste Grease - eBay (item 260651877550 end time Feb-12-11 17:21:37 PST)

 

Because there is a gap from the removal of the original crappy thermal pad?

 

Not if you apply the thermal compound properly as I did.

 

No serious not every laptop is the same as yours.
There are some older Acers with a huge gap that can't be filled with paste (1-2 mm).
Also paste work best when only a thin layer is applied.

 

true different configs. as long as there is no air gaps thickness of layer not much of a problem. (we are not talking about huge thicknesses)

 

paste works best in a thin layer under pressure, that thermal conductivity will drop drasticly in the laptops where the shim mod works well.

 

sure ingenuity works well around here.
if something has good conductivity in a thin layer, what could be the reason
for it not to be conductive as well if it is applied thicker?

 

but if u can make a "block" of 1cm X 1cm X 1mm on the gpu, go ahead.

 

that is viscous enough to do that

 

Thickness is a component in heat transfer, and AFAIK different materials behave differently with different thicknesses.

 

true thickness is a factor in heat transfer calculations and it does play a role in rate of heat transfered.
Heat transfer rate is also proportional to thermal conductivity, heat transfer area as well as the temperature difference of two points. Like electrical voltage if there is no potential difference between two points there won't be any electrical current.
So if the temperature difference between two points is so low doesn't matter what you do you won't be able to remove the heat from one point to another.

So your arrangement might be sufficient enough to remove the heat from GPU and memory chips. But all I was saying was this compound has much better thermal conductivity so the result will be higher heat transfer rates provided that there is enough temperature difference between the two points. Meaning you may be able to transfer heat from one point to another so quickly but if you can't cool the second material quick enough, the temperature difference will be ~0 then from that point onwards you won't be able to remove any heat from GPU.

The bottom line is everything needs to be balanced (ambient temp,cooling fans speed, number of fins, area of fins, the length of copper arm and etc.) and your arrangement may be sufficient.

Since we don't know all the variables and factors involved, nothing is certain and it becomes a trial and error. The only way to find out which way is better is to try out each config on the same PC and check the temperature changes that's all.

 

Yeah and the thermal conductance you listed for the paste will be when it is applied as a very thin layer.

 

whatever do as you like

 

Look, if the thermal conductivity of these pastes did beat that of copper, you would have hollow copper heatsinks filled with these pastes, or even aluminium (it would do better in that kind of test).

 

If you have enough money and engineering knowledge use diamond.

 

Once we have the advanced compression technologies it should be viable to manufacture diamond in one piece large enough, but until then, why not stick to what does work? I am sure a diamond shim would work nicely.

Diamond heatsinks would also be lighter.

 

With the acer thermal pad, my GPU reports 70C at idle. I'm sure that pad is rubbish.
Can't fill the gap with Artic Silver 5, so for approx the same price as a thermal pad replacement off ebay (for which I've no idea if it will be better), I can get a small copper shim.

Can't hurt, can it?

 

Some posts got deleted. Accusing someone of trolling is trolling too.
It's getting nowhere so why not just leave it?

For whatever reason discussions on thermal pastes always end up in a flame war.
It seems thermal compounds are better at heating things up rather than cooling them down

 

Can't hurt, didn't hurt.

Idle is now 10C cooler.