Aluminum vs copper heatsink - laptop advice

[rescuetoaster]

Hey guys,
I have a Toshiba Portege r700-s1320. I love this little laptop, but my god does it run hot. I've got some specific questions and am looking for advice regarding a heatsink I picked up for it.

The first image you see is the factory heatsink - it is a VERY thin aluminum plate (seriously, it bends like paper). The part that is circled in red is the part in question. It doesn't appear to actually make contact with anything directly underneath it on the motherboard. I am sure the fins (the raised notches you see) are there to improve cooling. Keep that in mind as you look at picture two. This is a picture of the heatsink they shipped on the portege r835 model (newer version of mine). It shipped with a copper plate that is probably double the thickness of my aluminum one, but it doesn't have that extra area with the raised fins like the aluminum one.

The reason for this thread is I'm wondering you guys think it will be worth it to try and install the copper sink? The green circle is an area I would have to cut off of the copper plate to make it fit on my laptop. What is a good tool to cut copper like that without bending it?

Last question is regarding TIM installation. So far I've done two applications of just putting a small amount in the center of the CPU and letting the heatsink pressure spread it - is it better to spread it manually on mobile intel chips?

 

[Tech Tweaker]

As far as thermal paste, I've always just put a dot in the middle of the die on laptops. Never really seen the need to spread it.

 

[rescuetoaster]

That's my go to method for desktops, but I was shocked at how poor of a difference applying MX-2 made. It may have actually gotten slightly worse as far as cooling. I'm definitely going to apply a little less next time around.

 

[doyll]

That aluminum plate looks like it might be a baffle to guide airflow rather than a heatsink??

 

[RnRollie]

That aluminum plate looks like it might be a baffle to guide airflow rather than a heatsink??

Yes, that is my impression also...

 

[rescuetoaster]

So are you thinking it's necessary/better than the copper one? As far as I can tell, the 835's chassis and air flow setup is the same, so I can't see a reason that that section would be necessary if they didn't include it on the newer laptop.

 

[doyll]

So there are two motherboards / systems here:

• Yours with thin aluminum that contacts on one side and not on other.
• The newer version with a copper plate contacting components on left side.

Where does the fan set.. is it over the right side blowing into the fin pack?

In other images I see when googling have a black back except where it contacts CPU.

Are all other components the same in both models?

 

[rescuetoaster]

In the first picture (the R700) you can see the black fan on the bottom of the picture - it pulls air from the bottom of the chassis, and blows it across the aluminum heatsink, and it exits the side through the aluminum fins (we are seeing what lies right under the keyboard in this picture). It's the same airflow pattern on the newer R835, but as you can see the copper (installed on all R835s) setup doesn't have that area with the raised baffles. As far as I can tell, these are the main differences between cooling systems in the R700 vs R835. As you said, that baffle area on the R700 doesn't make contact with anything underneath it.

I'm tempted to just test it out, but I don't know what cutting tool would work best to cut off that green area on the copper plate.

 

[NiHaoMike]

Use a "nibbling tool" to trim that corner.

 

[larrymoencurly]

If you use tin snips or a nibbling tool to cut off part of the copper plate, you could warp the plate enough so it doesn't make good contact with the chip it's trying to cool. The best way to cut the copper without warping it is with a Dremel cutoff wheel.

I'm guessing the aluminum heatsink is bigger to make up for it being thinner or for the inferior conduction of aluminum vs. copper. OTOH I thought most of the heat was sucked up by that heatpipe.

The only way to tell if the heatsink grease is going on properly is to apply it, attach the heatsink, then take them apart to see if both surfaces were completely coated.

 

[doyll]

Give it a try. I assume you have a R835 heatsink. Dremel with cutting wheel or jewelers saw. Does it have to be cut off to fit over something? If it's not than just leave it.

 

[rescuetoaster]

Yeah, I got one off of ebay for about 3 dollars a while back. It does need to be cut as there is a cap or something on the motherboard that is blocking it.

I'll see if I can find someone with those tools and I'll just try it out.