Core 2 Duo heatspreaders

[neuralnut]

Had a lot of temperature problems with my E6400, I'd reseated the HSF a couple of times and got large variations in temps. Finally pulled the CPU out and had a close look at it, basically a straightedge touched the IHS at the edges but not in the centre.

I lapped it for a short time, and as you can see from the enclosed photo, the lapping hardly touched the center of the IHS - all the meat was taken off near the edges.

Put it back in and it ran 8 degrees C cooler under load. So the lesson is, if your conroe runs hot, check the IHS, some are not nearly flat enough.

 

[cmdrdredd]

I don't know about mine. I'd never lap it though...i just can't see myself scratching up this baby

 

[Maximilian]

Nice job on fixing that dude :thumbsup:

 

[DJ Mike]

So what temperatures are you seeing before and after? Using Core Temp or mobo readings? Just saying 8C doesn't provide much to go on!

 

[Keysplayr]

Wow, that shows the heat spreader being extremely concave for something thats supposed to be flat. Do you think you could have gone further with the lapping? Or do you thing you would have gone too far and sanded through the edges?

 

[cmdrdredd]

Originally posted by: keysplayr2003
Wow, that shows the heat spreader being extremely concave for something thats supposed to be flat. Do you think you could have gone further with the lapping? Or do you thing you would have gone too far and sanded through the edges?

I just finished lapping mine all the way down to the bare copper. Fron my original temps that hovered at 55c at idle and up to 75c at load it dropped to 47c at idle and only 60c at load. A Far cry from where I was before. I went from 600grid to 800 then up to 1000 and stopped there. I suppose I could go to 1500 and 2000 to achieve a mirror finish but it's really not necessary. I wanted only for it to be a flat mating surface for my HSF which seems to have worked.

 

[NoStateofMind]

Shoosh. Until 2 days ago I knew nothing about "lapping". But I do know what it means now thanks to this link.

Lapping your Core 2 Duo

 

[Baked]

Originally posted by: PC Surgeon
Shoosh. Until 2 days ago I knew nothing about "lapping". But I do know what it means now thanks to this link.

Lapping your Core 2 Duo

Nice guide. I noticed there are 2 methods of doing the lapping, one that involves circular motion and one that involves going back and forth. I wonder if it really affects the end result. From what I've seen, both methods give you the mirror finish in the end.

 

[cmdrdredd]

Originally posted by: PC Surgeon
Shoosh. Until 2 days ago I knew nothing about "lapping". But I do know what it means now thanks to this link.

Lapping your Core 2 Duo

That's about how my IHS on the C2D looked. Except it wasn't as pretty. I'm going to move up to 1500 and 2000grid and lap again just to clean it up then I'll take a picture.

 

[imported_sjm]

Do you really use grease when lapping these things? How do you hold on to the CPU without damaging it?

 

[Baked]

Originally posted by: sjm
Do you really use grease when lapping these things? How do you hold on to the CPU without damaging it?

You don't use grease, you use water. Some people use dense foam, others use the tray that comes with the CPU.

 

[cmdrdredd]

Originally posted by: Baked

Originally posted by: sjm
Do you really use grease when lapping these things? How do you hold on to the CPU without damaging it?

You don't use grease, you use water. Some people use dense foam, others use the tray that comes with the CPU.

No water at all here...you can put a few drops of water on the area of the paper you're working with if you want. It's not necessary though.

I got the wet/dry sandpaper from the local advance auto parts store. You get 5 sheets for about $3 or so. I got 600/800/1000/1500/2000 grit and moved in increments. It's next to impossible to do any damage to the CPU whatsoever as long as you keep it flat on the surface you're going to be working on. I'll post some pictures of my final result after I finish with the 1500 and 2000grit paper.

 

[Baked]

How often do you change the grit of sandpaper after you get to the copper? Like every 5 minutes?

 

[Conky]

Interesting thread! :thumbsup:

I will probably try lapping my E6400 when I get a better overclocking motherboard and DDR2 and PCI-E videocard although right now it's running pretty cool.

 

[cmdrdredd]

Originally posted by: Baked
How often do you change the grit of sandpaper after you get to the copper? Like every 5 minutes?

When you get no resistance between the back and forth movement of the IHS and the paper is when you move up to the next grit. I usually did about 2 minutes changing the direction I sanded the IHS every 20seconds or so.

 

[cmdrdredd]

Originally posted by: Beachboy
Interesting thread! :thumbsup:

I will probably try lapping my E6400 when I get a better overclocking motherboard and DDR2 and PCI-E videocard although right now it's running pretty cool.

Yeah I was worried at first myself, but after doing it it's damn easy (no pins to bend/break on a LGA775 CPU). I'm trying to aquire a digital camera to get some pictures up. I finished up with the 2000grit paper and it's looking almost as clean as the bottom of a copper Heatsink when it's out of the box. It has a super clean mirror finish.

 

[imported_sjm]

Why does that linked guide mention elbow grease if none should be used?

 

[Baked]

Mmm... I don't plan on selling this E6400, but I do have a pretty flat IHS on it and the default temp's low compared to all the guys w/ warped IHS. I don't know if I should lap it. I do have the wet/dry sandpaper set from previous HSF lapping projects.

 

[cmdrdredd]

Originally posted by: Baked
Mmm... I don't plan on selling this E6400, but I do have a pretty flat IHS on it and the default temp's low compared to all the guys w/ warped IHS. I don't know if I should lap it. I do have the wet/dry sandpaper set from previous HSF lapping projects.

If you're happy with it thus far don't change it. Likely you won't get any difference. This is merely for those who have a 100% working CPU and motherboard/memory combo that have a issue with a concave/convex (i.e. not flat) IHS on their C2D or any CPU for that matter.

 

[cmdrdredd]

Originally posted by: sjm
Why does that linked guide mention elbow grease if none should be used?

Because my elbo/arm hurt after doing the circular motion for 15-20minutes removing the silvery nickel plating from the top layer :laugh:

 

[Conky]

Originally posted by: Baked
Mmm... I don't plan on selling this E6400, but I do have a pretty flat IHS on it and the default temp's low compared to all the guys w/ warped IHS. I don't know if I should lap it. I do have the wet/dry sandpaper set from previous HSF lapping projects.

Why fix what ain't broke? You have a nice overclock already and a lapped cpu has no warranty.

 

[Baked]

That's true. I do have a bad habit of buying things I don't need and fixing things that are not broken. I'll spare this one the misery for now.

 

[cmdrdredd]

Ok I'm all done. fully lapped C2D. Pictures below with my system specs and before+After temps. I included a screenshot of CPU-Z and core-temp too

Antec P180 case with the intake and rear exhaust fan on high top exhaust on low
Seasonic S12 600watt PSU
Asus P5B Deluxe at 400Mhz FSB
Corsair XMS2 6400 at 5-5-5-12 w/2.1v
C2D E6400 @ 3.2Ghz at 1.34v
Zalman CNPS9500LED

Before lapping I had a concave IHS and my idle temps at these speeds was almost 55c. Load was up past 65c all the time, and it hit 70c at one point. Not good. After lapping I hot load at 60c and idle around 47-48c. This is a very good result with no other changes.

Typical IHS from a P4 for refrence

My fully lapped IHS from my E6400

Notice the nice reflective surface

Screenshot of CPU-Z etc

 

[Dethfrumbelo]

You'd think that Intel could've gotten on this problem by now. How many different procs have had these crappy heat spreaders?

Not only did you benefit from a much flatter surface, you've got direct contact with the copper, which is helping temps a little. If you lap the nickel off the bottom of your heatsink you'd probably see temps drop a little more.

 

[cmdrdredd]

Originally posted by: Dethfrumbelo
You'd think that Intel could've gotten on this problem by now. How many different procs have had these crappy heat spreaders?

Not only did you benefit from a much flatter surface, you've got direct contact with the copper, which is helping temps a little. If you lap the nickel off the bottom of your heatsink you'd probably see temps drop a little more.

My heatsink is pure copper and has a glass smooth finish still. Zalman 9500LED

Although I'm probably going to be upgrading to a Thermalright Ultra-120 and Panaflow L1A down the line.

I do agree, Intel should have this fixed, and I don't ever remember hearing that AMD had such issues.