Asus Gpu Heat Fix?

So I've got an Asus m51sn, and I recently took it apart to clean it up and get it running cooler. Put new thermal grease on it, undervolted a bit, and now the CPU is running cool as a cucumber (58C on stress test). Only problem is the GPU. Under stress test, it runs up to 90C and the fan doesn't speed up at all, since its speed control is linked only to cpu temp. I've tried every fan control program I could find and none of them will work with my laptop fan. No fan control in BIOS either.
So, I've got a copper pipe that goes from my gpu to the block the fan is attached to, and I've got a copper pipe going from the CPU to the fins that the fan blows across. I'm thinking about soldering a copper bar between the two heat pipes to share heat between the gpu and cpu, thus turning up the fan to cool them both when either heats up.
So my question is: am I a complete idiot or is this really doable?

 

As far as fan control no surprise there. Not terribly surprised about the GPU not causing the fan to spinup but it is odd.

Connecting the heatpipes may have some effect. But it wont be as positive as you want it to be. Nor do i think it will actually heat the CPU up enough. Control point on myne i believe is 70 on either unit.

Remember that the stock heatpipes are vacuum sealed hollow tubes. If you damage that in any way they wont function properly so if you decide to do something dumb, dont damage the pipes or put holes in em.

 

Did you take the thermal pad off the GPU heatsink? I had one of these laptops a while back, and I think it used a pad instead of thermal paste on the GPU.

If so, buy a thermal pad ASAP.

 

Yeah, it had a thermal pad. I can't imagine going out and buying one, tho. It was aluminum and it couldn't have been any thicker than foil used in the kitchen. Seriously, it was that thin. I think cutting a square of aluminum foil would be just as substantial. I could buy a copper shim, though. Would that be better? btw, it had a good thick gob of thermal paste on the back side of the pad.

 

Where do people get the copper shims?

 

You find the thickness and dimensions you need, and then go to a place such as a hardware store (Lowes, Home Depot, Ace Hardware) and find the appropriate thickness, and then either buy a sheet to cut yourself or get someone to cut it for you. You can also try eBay.

 

Note taken. I'll do my best not to damage the existing pipes. I don't plan on altering them in any way other than applying a little solder to them.

As far as the gpu pad, I'm fine with getting a pad put on there, and that may cool it down a little bit, but that doesn't fix the fact that the fan will not turn on for a hot GPU, only a hot CPU.

So, hopefully, I'll get a copper shim and bar today so I can start playing.

 

Just a word of warning, be careful with copper shims. Improper installation can completely wreck the GPU die.

 

Bummer, couldn't find any copper locally. Gonna have to order online.

 

so does it use the internal CPU temp sensor to control the fan ? ... or it has a separate sensor somewhere on the main board ?

 

Best I can tell, it uses cpu temp, because when i stress test it, fan seems to speed up incrementally with cpu temp, not any of the others. another disturbing fact: when i stress the cpu and gpu together, the fan spins up and cools the cpu but not the gpu, even though the copper pipe for the gpu is attached to the block that houses the fan. maybe there's more to this shim business than I gave it credit for...
but if i wasn't getting good contact between the gpu and the heatsink, i'd think it'd heat up more than just 90C. We'll see. I'm ordering the shims on eBay now.

 

Alright, got my shim and my plate in today. Closest I could find for a bar to transfer heat from gpu heatsink to cpu heatsink was a copper electrode plate. A hair under a millimeter thick, 3/4 x 5 inches. gonna cut it in half lengthwise to make it narrow enough for the board, then solder it on and see if it works.
I honestly have misgivings about this. I'm thinking that the gpu is going to heat the cpu too much and have the fan running nonstop. That's what I think, but obviously not what I hope.
So, fixing to shut down and start pulling it apart. Will take pictures and post results.

 

Sounds good, I love pictures of laptop mods

 

Well, that was a big bust. I can't for the life of me get that solder to melt on copper. The copper just sucks the heat out of it so dang fast, it will not be liquid and in contact with the copper at the same time. I even tried putting a few beads of solder on the pipes where the ends of my bar would attach, then holding the bar over a gas stove fire to get it screaming hot. The instant I set that bar onto the solder, it cooled. I could get the solder to melt enough to form a flattened circle, rather than a bb, before it cooled and hardened, but that was it. I don't know what else to do. HELP!!

 

Well, here's what I was trying to do. Anyway, I realized after that picture with the solder on it that I needed to score the copper to give the solder something to hold onto. Still a no-go, though.

 

Maybe you should buy some thermal adhesive and try that instead?

 

That is a great idea. I had thought about adhesive, but I didn't know there was anything available that transferred heat that well. That's what I'm going to do. Now to wait for the arctic silver adhesive to get in. Should be Monday or Tuesday.

Arctic Silver Thermal Adhesive

 

Ok, I got the adhesive yesterday and glued my copper strip down to the two pipes. Today I ran my tests and it seems to be a bust. The CPU actually seems to test a few degrees cooler, but the GPU still gets just as hot.
Something I forgot to mention earlier, though, was that I did find out that the fan does turn on for the GPU and does cool it a little. When the GPU hits 95C, the fan comes on until it gets down to 92C, then cuts back off. Pretty weak, I think. Anyway, the new copper strip does nothing to slow down the heating of the GPU or to speed up the cooling. I'll try it without that copper shim, its a bit thick, I think, and maybe I'll get some better results. For now, though, here's what I was getting.

Orthos test on the CPU


Furmark test on the GPU


I forgot to take a picture of the mobo before I put the panel back on. I'll put it up with next post.

 

Here we go. I took out the copper shim from the GPU, and I had to up the voltage up just a hair to keep from bsod'ing when I ran orthos and furmark at the same time. So I ended up with higher CPU temps, but the GPU ran cooler. In fact, it never reached 95, unlike previously when it ran up to 95, then fan cooled it down to 93, then right back up to 95, and so on. It touched 94 for just a second this time, but really it sat on 93 and 92 for the duration of the test.



All in all, it didn't help A LOT, but if furmark can't make it get up to 95 to make the fan cool it down, who knows how much heat its really drawing off. Without the fan, it may have run up to 100 or higher, who knows? So, in that light, I say the bar is a success.