Wow, lapping is amazing!

[crapfest]

So I finally took the dive and lapped my CPU and heatsink. I have a Q6600 G0 and the original Thermaltake Big Typhoon. I was having second thoughts at first about doing it, but after reading all of the different results people were getting, I decided I would give it a try (especially since the processor was working fine and I wouldn't need to RMA it).

Here are my results (note: voltage was kept at default for all measurements):

2.4ghz before lapping:
Idle: 32°C, full load 59°C

2.4ghz after lapping:
Idle: 23°C, full load 45°C

3.0ghz before lapping:
Idle: 36°C, full load 65°C

3.0ghz after lapping:
Idle: 26°C, full load 49°C

I lapped both the CPU IHS and the heatsink base starting with grit 200 then working my way through 600 and finishing it off with 2000. After the hundreds of passes with 2000 grit back and forth (rotating by 90 degrees every 50 laps or so), they were both as shiny as a mirror.

Also, before there were huge discrepancies between the core temperatures for the different cores... now they are all nearly identical.

Pic of results: http://img172.imageshack.us/img172/8530/lappinghj7.jpg

Needless to say I'm very happy with this overclock. I encourage anyone who's on the fence about it to take the plunge as I did. Time to go see how high I can OC this thing...

 

[Tempered81]

nice i plan to lap my e8400 & thermalright ultra -120.

nice to see your 15c temp drop under load

which lapping guide did you go by?

 

[ghost recon88]

I just lapped my Thermalright Ultra 120 Extreme in anticipation of my E8400. As soon as I know my chip isn't DOA, I'm lapping it too.

 

[Phunk0ne]

I lapped both my tr U-120-E and my E6750.
*note*
I have undervolted my 3.2GHz overclock from stock to 1.25 in BIOS, Everst shows 1.2V Idle & 1.184 Load

lapped U-120-E & E6750

unlapped:
@3.2GHz
Idle: 32C
Load: 47C

@3.6
Idle: 35C
Load: 52C


Lapped:
@3.2GHz
Idle: 24C
Load: 37C

@3.6GHz
Idle: 26C
Load: 46C

 

[quackerww]

Sorry I did a search and found nothing short and simple on what Lapping is...

Any one answer my question... "What is lapping?"

 

[WaTaGuMp]

Originally posted by: quackerww
Sorry I did a search and found nothing short and simple on what Lapping is...

Any one answer my question... "What is lapping?"

Lapping is sanding the surface of both the CPU and the HSF to make them smooth enough to not have any gaps to possibly trap air. Some just lap the CPU some just the HSF and some both. In simple terms its making the surfaces at flat as possible over how they come from the factory.

 

[TheVrolok]

So do you then use any thermal compound between the two, or are they supposed to touch so tightly that there's no need?

 

[Phunk0ne]

Well yes. Unlike you would use it normally, when you have both your IHS and Heatsink lapped, you only need a very thin layer of thermal past, thin enough to see the copper color of both surfaces. A small dab and spread it out with a creditcard type card, I used a razor.

I used this site as my basis for lapping:
Overclock.net Lapping guide

I started @ 200 grit, worked my way through 400, 600, 800, 1500. And then finished it with brasso, and then cleaned it off with artic cleaner.

I used 4 strips of each grit and worked my way up. Took me about 2.5-3 hours before I was done. You really want to take your time while lapping, but when doing so, it is rather easy to get a mirror finish =)

 

[LittleNemoNES]

Originally posted by: ghost recon88
I just lapped my Thermalright Ultra 120 Extreme in anticipation of my E8400. As soon as I know my chip isn't DOA, I'm lapping it too.

This is SO obvious...BUT I made the mistake of being so anxious to get started on my last build that I lapped my e6600 without testing for DOA first. I was lucky it was fine -- especially since I bought it back when it cost ~$500+

 

[Idontcare]

Originally posted by: TheVrolok
So do you then use any thermal compound between the two, or are they supposed to touch so tightly that there's no need?

I lapped a G0 and a Tuniq. Just for kicks I tested it without thermal paste. Got the same temps as when I used TX-2 and same overclockability.

So technically, for my specific lapped CPU and Tuniq, thermal paste was not necessary.

I use the thermal paste anways as when properly applied there are no downsides to using it (the excess should naturally squeeze out from between the IHS and HSF over time) just to give myself margin and ease of mind.

 

[21stHermit]

Originally posted by: Idontcare

Originally posted by: TheVrolok
So do you then use any thermal compound between the two, or are they supposed to touch so tightly that there's no need?

I lapped a G0 and a Tuniq. Just for kicks I tested it without thermal paste. Got the same temps as when I used TX-2 and same overclockability.

That tells me that thermal paste is a crutch used by the manufactures to avoid tighter tolerances. Stands to reason if you have perfect contact then no thermal paste is necessary.

Now the question, am I brave enough to trust my statement and forego thermal paste?

 

[Idontcare]

Originally posted by: 21stHermit

Originally posted by: Idontcare

Originally posted by: TheVrolok
So do you then use any thermal compound between the two, or are they supposed to touch so tightly that there's no need?

I lapped a G0 and a Tuniq. Just for kicks I tested it without thermal paste. Got the same temps as when I used TX-2 and same overclockability.

That tells me that thermal paste is a crutch used by the manufactures to avoid tighter tolerances. Stands to reason if you have perfect contact then no thermal paste is necessary.

Now the question, am I brave enough to trust my statement and forego thermal paste?

There is no bravery needed assuming you are using an Intel chip, if you really should use thermal paste but you erronously chose not too then the chip will just thermal throttle. No harm done and you will have answered your question.

It is very likely though that you will find your system does just fine if you lapped both the HSF and IHS. If you haven't then $1 of thermal paste really is not a crutch if you think about it. For a buck you buy yourself a huge margin for unflat and warped IHS and HSF surfaces. Not bad tradeoff.

 

[CTho9305]

Originally posted by: Idontcare

Originally posted by: 21stHermit

Originally posted by: Idontcare

Originally posted by: TheVrolok
So do you then use any thermal compound between the two, or are they supposed to touch so tightly that there's no need?

I lapped a G0 and a Tuniq. Just for kicks I tested it without thermal paste. Got the same temps as when I used TX-2 and same overclockability.

That tells me that thermal paste is a crutch used by the manufactures to avoid tighter tolerances. Stands to reason if you have perfect contact then no thermal paste is necessary.

Now the question, am I brave enough to trust my statement and forego thermal paste?

There is no bravery needed assuming you are using an Intel chip, if you really should use thermal paste but you erronously chose not too then the chip will just thermal throttle. No harm done and you will have answered your question.

It is very likely though that you will find your system does just fine if you lapped both the HSF and IHS. If you haven't then $1 of thermal paste really is not a crutch if you think about it. For a buck you buy yourself a huge margin for unflat and warped IHS and HSF surfaces. Not bad tradeoff.

Don't the AMD CPUs+mobos protect chips too? It will shut off rather than throttling, but if it shuts off while you're testing, you'd know why...

 

[crontab]

Just wondering about lapping. Has anyone here ever read about damage caused by lapping? I doubt anything can be harmed when one laps the HS, but how about the CPU? The chips nowadays come with their own copper heat spreader unlike the chips in the past... where it was fairly fragile and some people could've crushed them just by installing a HS.

I can't really think of anything, other than a good amount of sanded off metal shavings getting caught under the cpu... other than that, overlapping is probably something that is fairly tedious and difficult to do...

thoughts?

 

[sgrinavi]

Nice job, but be careful.. I got flamed for posting good results with my lap job....

 

[Avalon]

I've been hearing a lot of good lapping stories lately. I think I'll lap my E8400 when I get it. Maybe

 

[Idontcare]

Originally posted by: CTho9305

Originally posted by: Idontcare
There is no bravery needed assuming you are using an Intel chip, if you really should use thermal paste but you erronously chose not too then the chip will just thermal throttle. No harm done and you will have answered your question.

It is very likely though that you will find your system does just fine if you lapped both the HSF and IHS. If you haven't then $1 of thermal paste really is not a crutch if you think about it. For a buck you buy yourself a huge margin for unflat and warped IHS and HSF surfaces. Not bad tradeoff.

Don't the AMD CPUs+mobos protect chips too? It will shut off rather than throttling, but if it shuts off while you're testing, you'd know why...

I believe this to be true (what you wrote) but my last AMD chip was an Athlon XP 1900+ so I am not 100% confident in what AMD's thermal protection is capable of these days so I did not want to say something which might not be true.

Thanks for setting the record straight for me and the other readers.

 

[CTho9305]

Originally posted by: Idontcare

Originally posted by: CTho9305

Originally posted by: Idontcare
There is no bravery needed assuming you are using an Intel chip, if you really should use thermal paste but you erronously chose not too then the chip will just thermal throttle. No harm done and you will have answered your question.

It is very likely though that you will find your system does just fine if you lapped both the HSF and IHS. If you haven't then $1 of thermal paste really is not a crutch if you think about it. For a buck you buy yourself a huge margin for unflat and warped IHS and HSF surfaces. Not bad tradeoff.

Don't the AMD CPUs+mobos protect chips too? It will shut off rather than throttling, but if it shuts off while you're testing, you'd know why...

I believe this to be true (what you wrote) but my last AMD chip was an Athlon XP 1900+ so I am not 100% confident in what AMD's thermal protection is capable of these days so I did not want to say something which might not be true.

Thanks for setting the record straight for me and the other readers.

That was a question. I don't know for sure. It's not a guarantee. Don't go whining to AMD if you kill your chip assuming I know what I'm talking about .

 

[PolymerTim]

I've got an older Athlon XP 2500+ (Barton) and I can confirm that it has thermal protection, although I'm not sure if its built into the CPU or the motherboard (don't even remember what MB I've got). The first time I took it apart to dust the HSF, I didn't realize that you had to reapply a fresh TIM. Mine came with one of those waxy thermal pads and I tried to just stick the HSF back on. It went on fine, but the computer kept turning itself off after about 1 minute from boot. It took me a little while before the obvious answer hit me (Doh!).

 

[BonzaiDuck]

crapfest -- I have to ask you.

I finally took the plunge on IHS lapping with an E6600 processor. Graysky, the OC'ing guru, had posted a thread with pictures at another forum.

In Graysky's post, he had lapped off all the nickel plating on the processor, and it showed only copper. Copper, of course, has a higher thermal conductivity and lower thermal resistance than nickel.

When I lapped the E6600, I only checked it with a straight-edge for flatness before I stopped lapping, and there was still a nickel layer on the surface.

Did you go down to bare copper?

 

[BonzaiDuck]

Tell me your room-ambient for the data in the OP. Just so I can remember checking back here, mine was 64F with 20C idle temperature on the lapped E6600. I should probably check my data from last summer on the same processor, and normalize it for the room-ambient.

 

[taltamir]

3 hours? that is SOOO much work... ouch. I would only lap my cpu and heatsink when the added speed (due to overclocking) would be greater then spending an extra 3 hours worth of income on a CPU. The problem there, is that I am certain that lapping the CPU voids your warranty, and if you are lapping a core2 quad extreme that cost 1000$ that can really hurt.

 

[crapfest]

BonzaiDuck - I went down to bare copper with just the 200 grit then kept going just for good measure. Then I took off some more during the process of going through the higher grits. Also, the ambient temperature was 22°C.

Taltamir - The warranty thing is almost a non-issue. CPUs very rarely die on their own unless you really torture them (extreme voltages and such), so using it for a day or two without problems pretty much guarantees that you won't need to RMA it. After that point, three hours of time is worth the rewards in my mind. Obviously your own opinion may differ.

 

[thegisguy]

I'm pretty sure the AMD thermal protection is built into the Motherboard not the CPU. I seem to recall using a Gigabyte MB with an old 1800+, and a month after I got it New MB's came out with thermal protection. Oh Well. My 2 cents.