Can I lap this NOTEBOOK heatsink?

hi guys - this is the heatsink of my aspire 5051 notebook. I've been reading a lot in the last couple of weeks about cpu lapping and I bought a new cpu for the notebook. i've decided to change the cpu and lap the heatsink.

i still haven't removed the old cpu but i noticed the the heatsink has a strange form. Take a look at the attached photo - the cpu is just under the place marked with the numbers 2 and 3 (lefr ftom the fan). And what seems to be the GPU is under number 4 (upper left corner) I saw that the gpu is about 1,5 mm thinner than the cpu and the downside of the heatsink goes lower at number 4 (with about 2 mm!).

The whole thing is the way you see it on the picture. do you think it can be lapped?

If yes how? because of the form i cannot use a sandpaper, because part 4 is lower than part 2-3. how can i lap it?

by the way, has anyone seen the deassmeble guide / service manual about the 5050 series?

 

Oh, I'm sure you can lap it with sandpaper. It's just gonna be difficult to a downright pain the butt. Assuming, the places of contact are "lower" than everything else, when you're running one of the "upper" parts over the sandpaper, you're just gonna have to do it off the edge of a table or something. How you make sure you're getting an even lap is probably the hard part.

Furthermore, laptop sinks sometimes don't make direct contact with a GPU or NB, but go through a thermal pad instead. If that's the case, lapping the sink is going to have little to no effect.

 

What you want to do, is glue a piece of 220grit sandpaper to a block of flat wood or steel. Then just rub your entire heatsink over it, making it pretty level.

K-TRON

 

Naw, I'd think he'd want to keep the height difference between the two planes of contact to make up for the height difference between the GPU and the CPU. Otherwise he'd definitely have to use a thermal pad somewhere if he didn't before.

Of course if there was a thermal pad somewhere to begin with, K's might be the better (and far easier) solution.

 

And does anyone have an opinion how much temperature drop might be expected vs thermal compound by itself. Lot of trouble it seems for relatively minimal returns I would think. In a Desktop with serious tweaking I could see. You can add fans to increase dissipation of the greater amount of heat being transfered to the heatsink. In a notebook usually not an option, it seems to me you could in theory, if your passive cooling method (heatsink) over powers your active cooling method (fan) increasing the passive will stop getting returns? So any opinions as this is all new to me. Seems like a great idea when you can add a fan (increase active cooling) and increase the temperature differential between case temp and core temp but in a notebook much less case temp depression vs core, ergo minimal to no improvement?

 

Lapping a heatsink is a bad idea in general, the best heatsinks are very smooth on the base, I mean like micrometers are used to determine the surface roughness. You will not be able to get even remotely close to flat if you dont use something around 1200-2000 grit sandpaper.
As mentioned you will notice no difference by sanding the heatsink down.

Just undervolt your processor with rightmark and that should be enough to keep the temps down a bit.

K-TRON

 

As noted you're not going to see a difference . . . maybe a degree or two, if that. Lapping only really comes into play with the CPU heatsinks in desktops.

 

are there performance heat sinks for laptops?

 

Yeah as mentioned above....not much of a return for the work done! I did this on my everex xt5000t ( horrible temps in that thing!) and got 1-2C decrease, and I was very meticulous about it.

 

There are no performance heatsinks for laptops.
Well if you have a 3 arm C and C machine, and a nice block of copper and computer deisign skills you could make your own.
Its not really worth the effort.
Just find a program which you can control the fans with.

K-TRON

 

If you can expand the surface area vs mass of the heatsink you will be right where you want to be!

 

thank you guys for all the relies. I'll see what i can do. but the fan is always on and this drives me crazy. I've decied to change the cpu of the notebook and since the new one is powerful than the old one i have tp expect more heat. so laping the heatsink can give me back the temps with the old cpu (i hope). therefore i think it is good idea.
(turion mk36 -> turion x2 tl-60)

i saw that there is a thermal pad beween the gpu and the sink. and i'm gonna rip it off and replace it with arctic silver 5. about the cpu - i still don't know what's in between but i have to change it with the new processor - so again acrtic silver 5 here.

And when lapping i have to keep the differences between the levels. so it'S going to be a pretty tedious task.

thanks again for the help.

Any other ideas?

cheers, peter

 

If you have the Tyler version of TL-60 vs Trinidad version the TDP is the same as the MK-36 31w so you might be in better shape than you think. Also the Arctic Silver in and of itself may do much to help. You might consider trying that first and see how it goes? Just a thought.

 

I've had to lap carbon seal faces and single mode fiber connectors. To achieve any measured gain you would need two matched mirror grade surfaces. This would call for lapping compound or 3M fiber optic polishing sheets, green and brown, and a glass lapping block.

I agree with the others, use a high quality thermal compound. Or do a chart with AS-5, or choice, then lapped with same thermal compound. Did you see a big difference? If you do it please post your findings.

 

yes, i bought the tyler version because of the tdp (31W is better than 35W in a notebook). and because i need to reassemble it in order to put the cpu i thought that i can use the chance to lap the heatsink. but as i said it has two levels/hights and it's going to be hard work.

and because the gpu and the cpu use a common heatsink i have to deassmeble the gpu too. i saw it uses a thermal pad but i don't know what's in the cpu. i intent to put actic silver 5 in both places - gpu and cpu. I know the gpu runs a way hotter than the cpu. should i make something else about the gpu? can the paste do its work properly? anything i have to look for when working with the gpu?

peter

PS. when done I'll post pictures and results. it the moment my cpu works at ~ 45C idle (no firefox just idle), with only firefox ~54C, under heavy load (linux kernel compile) ~ 72C. the vent goes on at about 49C and it is working almost all the time. i cannot messure the temp of the gpu because i'm using llinux.

 

..you could lap just the CPU. http://www.overclockers.com/tips31/

 

Remove the thermal pad and replace it with thermal paste. You'll see a huge difference in just doing that. Lapping is not a terrible idea since laptop heatsinks are all crap. You just need a piece of glass, a variety of wet/dry sandpaper, and a sink with running water.

 

ok, now i can confirm that amd tk-36 on aspire 5051 cannot be replaced with tl-60 (tyler version). they have the same TDP - 31W, socket S1 and everything else but the sink cannot cold the tl-60. aftre replacing it the system run for about 10 min and then the vent went off. it countinued for about 5 min and then the system turned off. it looked like a cooling problem. i replaced the pads of the controller and the gpu (on this notebook they all have a common heatsink) and after an hour i turned the pc on. this time it lasted about 45 secs. and the vent was on its maximuum before the system turned itself off. so now i have the pld mk-36, the old vent and arctic silver on the gpu and the controller.

what a waste for the tl-60. does anyone have an idea why it couldn't be cooled in this laptop? was it a failure or......... maybe faulty cpu?

 

i started new thread about this. here:
http://forum.notebookreview.com/showthread.php?t=227055

 

I would expect around a 2-5 degree improvement if the heatsink and CPU was lapped and made perfect contact with the CPU. It looks like a tricky operation but certainly not impossible. You could also see about replacing the tiny fan attached to the heatsink, that could improve circulation and drop a few more degrees too. Also, I would buy an angled stand with a fan and you'd see a nice temp drop from that alone.

*EDIT* as a note, if you do end up lapping I can vouch for using just 600 and 300 grit. 600 first and then 300 to finish. I lapped my e6600 and Tuniq Tower with these grits and ended up with an 8 degree improvement. After lapping I'd recommend scraping a credit card with thermal grease over the CPU to fill in any micro imperfections.

 

^^^^ What? you start with finer sandpaper 600 then move to 300? And you got an improvement? 600 is not fine enough to achieve what lapping is intended to do. Your fan advice? In a laptop. Oh and 300 grit will create more than micro imperfections, full on grooves.

 

what do u meen when u guys write lapping heatsink

 

It will make no difference in your temps. NONE.

 

Lapping =polishing, keep using finer and finer sand paper to get very very smooth surface on heatsink where it makes contact with CPU.

Why?
With very small imperfections prevents metal on metal contact. Air fills the void and air is a very very bad thermal conductor. Example you can reach your arm in a 400F oven, now stick your arm in 200F water. Water will burn you almost immediately air won't. So water is a good thermal conductor like metal is. The more metal on metal contact (less air) the faster heat can be transfered to heatsink and away from CPU. Using thermal paste accomplishes the same thing (remove air) but if it's out of budget and you have a lot of time and sandpaper lapping is the thing to do. I recommend saving up for the paste.

 

I have lapped the heatsink on my desktop and replaced the thermal compund with AS5 and noticed no difference at idle however at load it did drop my load temps by 8*c. I also replaced my thermal compound on my 8800GTX heatsink and it dropped my load temps by 8-9*c. Honestly i believe that just replacing the thermal compund with Artic Silver 5 will be better than going through the trouble of lapping.

 

You're right, I wrote it backwards. I used 300 grit then 600 grit. I measured an eight degree difference before and after so I think it achieved what it was supposed to do. You don't need a mirror finish to achieve flatness. Most heat sinks and CPU's come convex so any improvement is good enough for me. I don't have to see my reflection in the surface.

*EDIT* Also, the fan advice was more of a question as I've never done that mod; In the picture, there's a fan attached to the heatsink. I'm sure it's not the only fan that size in existence. A more powerful fan would make a good upgrade imho. Was it really necessary to be rude or are you just having a bad day?

 

Yes, lapping can certainly help with desktop CPUs and GPUs. But it will have no effect on a laptop.

 

I am going to out on a limb, it does not matter even for Desktops, if you use any thermal compound, it serves the same purpose. That is it.

 

my workstation and MCE are lapped. I lapped my CPU and heatsinks. the desktop temps dropped as much as 10-15C.

I remember my workstation before and after lapping
Q6600 OCed [email protected]
before lapping
idle:49C load:75C
after lapping
idle:38C load 59C
ambient temps are 29C


so one day I decided to lap my laptop also. mine is a old laptop HP nx8220, intel 2.33Ghz single core.(pre intel duo era)
all my systems i used AS5.
before lapping. fan locked @ 50%
idle 49C load above 85C
after lapping
idle 38C load 71C
if fans running @ 100% load is max 59C


my means of beachmark.
I used orthos and did small FFT test and let it run for 48 hrs before taking temp readings.

and yes, you have to run in AS5. I remember after lapping, temps reported as high as 82C. but it kept dropping.
AS5 runs in faster with higher temps.

 

good idea but obviously it is the only one fan that is on the market because of the following:
1. dimensions: 57x57x10. most of the fans are 60x60x15. it is vey difficult to find one that is only 10 mm thick.
2. voltage: 5w. the smallest ist 7w and the average is 12w.
3. this is just a fan blower. no "cage" around it.

SO i tried to find another fan. and it is very difficult to find one that is 10 mm thick and has 60x60. if so you have to cut the "cage" out in order to put it in the place. the one on the picture is a round fan and on the market there are only square fans. extra wholes should be made for the screws (with a bohring mashine ). and at the and the voltage: only 5w. tha smallest I found was 7w. since this is a notebook it is desinged for 5w and there is now way to get 7w from there. so you can forget it.

the fan on the pic has about 4-5 CFM power. I managed to find another one 60x60x10 5w from i chiniese company that has 13,6 CFM but it is sold at 100 items quantities. i need just one, not 100. otherway noone sell such things. don't forget we are not supposed to make such upgrades to laptops.

and at the end -> the fan is controlled by the bios. so even a powerful fan will spin less time bacuse it will cool the mashine faster but will be started more often.

so if someone can find something with the specs above, can give me the link.