If and when to lap a CPU.

[aCynic2]

I hear one should lap the heatsink and CPU to get the best surface contact, however, I'm certain that lapping a CPU voids the warranty.

So, should I run it first to make sure it works before considering lapping it? If I do that, should I not bother with a HS until I verify it at least works?

Any tips on how to proceed are appreciated.

 

[f4phantom2500]

you could try it out on a cheapo heatsink first...idk, the gains of lapping depend on how well you do it, and i think they'll probably be minimal. but it definitely voids the warranty. also be sure to record all of the info off of the cpu in case you need it down the line, cuz once you lap it that's all gone lol. if you don't overclock then there's probably no good reason to do it since it would void the warranty and you really won't need the extra cooling power if you aren't overclocking.

 

[aigomorla]

Originally posted by: aCynic2
I hear one should lap the heatsink and CPU to get the best surface contact, however, I'm certain that lapping a CPU voids the warranty.

So, should I run it first to make sure it works before considering lapping it? If I do that, should I not bother with a HS until I verify it at least works?

Any tips on how to proceed are appreciated.

ahahahhaha...

draw an X on top of the CPU with a sharpie. That shows you how much your shaving.

Use mineral or vegi oil to lub the paper. All you really need is one little drop on the paper.

The oil acts as a lub, and also a metal dust collector. Thats why i highly recomend it.


Go slowly, and lightly on the paper when you rub the cpu over it.

Also, a flat piece of glass or anything that wont bend to hold its flat form is highly recomended.


Also go in 1 direction.


SandPaper can be bought at any autostore. I highly recomend an autostore more then a hardware store.

Get these

700 900 1000 1500 2000

if your hs is very non flat, use the 700 first. You can check by putting the edge of the razor on top, and see if any light slips though.

900 is to start your mirror finish. 700 -> is techincally all you need.

1000 even more of a mirror finish

2000 and you get this:
http://i125.photobucket.com/albums/p73/aigomorla/IMG_0703.jpg

Ps. Thats my 600 dollar xeon. So dont freak out, a lot of people lap there IHS. ALso you WILL VOID warrenty the moment u shave it. Also you already most likely voided it when you overclocked, and pulled the stock heat sink off.

-Good luck.

 

[aCynic2]

Well, I'll definitely lap the hs. I don't mind wasting a HS. I bought the Thermalright Ultra-120 Extreme on Anadtech's review, but I'm starting to hear that the production quality is iffy. Some may get great results, some may get next to nothing.

 

[f4phantom2500]

Originally posted by: aigomorla

Originally posted by: aCynic2
I hear one should lap the heatsink and CPU to get the best surface contact, however, I'm certain that lapping a CPU voids the warranty.

So, should I run it first to make sure it works before considering lapping it? If I do that, should I not bother with a HS until I verify it at least works?

Any tips on how to proceed are appreciated.

ahahahhaha...

draw an X on top of the CPU with a sharpie. That shows you how much your shaving.

Use mineral or vegi oil to lub the paper. All you really need is one little drop on the paper.

The oil acts as a lub, and also a metal dust collector. Thats why i highly recomend it.


Go slowly, and lightly on the paper when you rub the cpu over it.

Also, a flat piece of glass or anything that wont bend to hold its flat form is highly recomended.


Also go in 1 direction.


SandPaper can be bought at any autostore. I highly recomend an autostore more then a hardware store.

Get these

700 900 1000 1500 2000

if your hs is very non flat, use the 700 first. You can check by putting the edge of the razor on top, and see if any light slips though.

900 is to start your mirror finish. 700 -> is techincally all you need.

1000 even more of a mirror finish

2000 and you get this:
http://i125.photobucket.com/albums/p73/aigomorla/IMG_0703.jpg

Ps. Thats my 600 dollar xeon. So dont freak out, a lot of people lap there IHS. ALso you WILL VOID warrenty the moment u shave it. Also you already most likely voided it when you overclocked, and pulled the stock heat sink off.

-Good luck.

omg...now i'm considering this lol. I mean...that pic is ****** cool. do you have to use any less thermal paste once you do this?

 

[WoodButcher]

Originally posted by: aCynic2
I hear one should lap the heatsink and CPU to get the best surface contact, however, I'm certain that lapping a CPU voids the warranty.

So, should I run it first to make sure it works before considering lapping it? If I do that, should I not bother with a HS until I verify it at least works?

Any tips on how to proceed are appreciated.

YES! Test before you lap, You may want to see if it will OC worth a damn before you spend the time lapping.
Personally I lap for flat only,600 / 800 grit, I don't care If I can see my ugly mug or not
I've read arguments for both sides, mirror finish and not. Some claim the micro grooves aid in transfer of heat because you get more metal to metal contact as the grease has channels to get out.
I have no clue.
I get good temps.
I'm not pretty like aigo so I avoid looking in mirrors.
Only the first sentence in this post was worth reading!

Nice work aigomorla. no joke, the extent you go to amazes me.

 

[Zardnok]

Get a straight razor. Hold your chip up to light and run the blade edge along the top of the heatspreader. Look to see how much light shows underneath the razor blade. The more light you can see between the razor blade and the chip, the more you need to lap it.

My chip was SO concave that I did not even bother running it before I lapped it. I knew it would suck, so I spent the hourish to get to mirror finish.

Also, I start with a much lower grit than others. I start with a 220 for about 5-10 minutes to take off the majority of the side portions where the problems exist the most on the C2D chips. After 10-15 minutes, I go to 400 grit, then 10-15 minutes and 600 grit, 10-15 minutes and 800 grit, 10ish minutes and 1000 grit, and then 10ish minutes and 2000 grit. For liquid, I get a smallish bowl filled with warm water and put a few drops of Dawn dish detergent in it. I then dab my finger into the bowl and tap it onto the sandpaper. This puts a single drop and I place the CPU upside down on top of the drop and circle around from there. After the paper gets soiled, I wipe off the chip with a paper towel, dab another drop on a clean section of the paper, and continue again with the chip on the fresh area. If I really want to put a mirror finish on, I use a sheet of printer paper dry for my final sand after the 2000 grit. Realistically, anything past 600 is probably overkill, but I have always been into overkill!

 

[graysky]

I'd say use a lighter oil like kerosene/heavy oils will be difficult to remove from your hands and the pieces you're lapping. Plus, you're screwed if you get oil inside/on the bottom of your CPU. Soapy water is good and cleans up well. Zardnok has the right idea.

Here are some links for you:

Lapped my Ultra-120 Extreme
Lapped my Q6600's IHS
Some detailed info about lapping

Let up know what you end-up doing.

 

[daveybrat]

I personally would never give my cpu a lap dance.



i'm too afraid i'd damage it or do more harm than good.

 

[graysky]

@daveybrat: I think there's actually little danger in doing it so long as you don't rush though it and are careful about what you're doing. Most people think that CPUs are these delicate and extremely fragile items, when in fact, they are pretty tough.

 

[Comdrpopnfresh]

so graysky- do you go in circle on the paper, or back and forth? whats the motion (i'm thinking about doing it on my x2 3800+ and a64 freezer pro). What should be put under the paper? How do you assure that whatever you use as a backing is straight?

 

[aigomorla]

OP, just google it.

There are tons of guides written.


Its not hard, just have patience with it, and yes its definitely worth it:

Look at my xeon right now loaded on all 4 cores:
http://i125.photobucket.com/albums/p73/aigomorla/NewTemps.jpg


I think thats my personal best with a loaded quad.

 

[graysky]

Originally posted by: Comdrpopnfresh
so graysky- do you go in circle on the paper, or back and forth? whats the motion (i'm thinking about doing it on my x2 3800+ and a64 freezer pro). What should be put under the paper? How do you assure that whatever you use as a backing is straight?

I read going in a circular motion isn't recommended since it is very difficult to keep even pressure with all that translational motion. Front-to-back-to-front is much easier to control. I used an 8x10 picture glass I bought at homedepot for $1.82. There's not real way I found out to check the glass for flatness. Mine seemed flat and given my results, I think it probably was

 

[Bill Kunert]

I used to work as a Xerox tech rep and I have an old platen glass from one of our large copiers. It's about a quarter inch thick and dead flat. You can also use a 12 inch square tile from Lowes or Home Depot. Many of them have machined surfaces.

 

[Zardnok]

Lucky me, the 6420 I just got in was incredibly flat for a C2D! Especially compared with the 6400 I got last month. I didn't even bother to install it with as bad as it was concave. I may eventually lap this 6420, but for now, I am enjoying it as is! With 15 minutes of bios fiddling, I am sitting at 3.4G with 1.4Vcore. 10 minutes into Orthos now. Will likely just let it run at this setting overnight to see if it is stable.

 

[swtethan]

yes lapping voids warranty, SO DOES OVERCLOCKING

 

[Comdrpopnfresh]

I decided to lap my ihs and hsf of my 3800+ and a64 freezer pro. I also decided to go through, take the heatpipe off of my a8n32-sli deluxe. I'm having a problem getting asus's gooey paste off of the north and south bridges, not to mention the pipe itself (its that slightly pink, flesh colored stuff). i was looking forward to putting on some as5.... BTW- how much does 700 900 1000 1500 2000 papers cost? I could see some light under a fresh razor on both, but mainly when i didn't hold it in the machined grooves of the hsf, and when i held it on ihs it was slight.

 

[SickBeast]

IMO lapping is too risky for what it gives you in terms of temps.

Just buy a better HSF, and use better thermal paste. The paste fills in the little gaps anyway.

 

[Comdrpopnfresh]

i might not- i have a feeling the paper will be expensive for one size, let alone those various ones. plus isn't wasn't too much light bleeding through. i have plenty of as5- so in 10 days (after the 200hr set) i'll make a decision. but any suggestions on the crappy pink paste? alcohol doesn't work well, neither does leaving alcohol stained paper on it....

 

[swtethan]

I just lapped mine tonight -7c-10c drop in temps, AS5 is fresh so it needs to set again. cost me $10 for the 320,400,600,800,1000,1500 paper. both my heatsink and cpu are mirror finish

 

[Comdrpopnfresh]

lol. not what i needed to hear. lol. I still think I'll let the system set for 10 days without lapping, see if i can even overclock any higher or it was cpu limited (as opposed to temperature). but this paste? I really need someone to comment on that. lol

 

[swtethan]

Hey if youre overlclocking it, you might as well lap it. Your warranty is gone either way. I thought I couldnt do it. but hey, here I am! I didnt use any oil, just dry automotive sandpaper the whole way, also with canned air to clean up.

 

[Keysplayr]

Originally posted by: aigomorla
OP, just google it.

There are tons of guides written.


Its not hard, just have patience with it, and yes its definitely worth it:

Look at my xeon right now loaded on all 4 cores:
http://i125.photobucket.com/albums/p73/aigomorla/NewTemps.jpg


I think thats my personal best with a loaded quad.

Very nice!! Hey, how accurate is that Core Temp program your using there? I ask because I downloaded ver. 0.95 and tried it on my E6420 (stock speed of 2.13GHZ and stock cooling) and Core Temp says I have a E6500.

Idle temps : Core 0 = 23C. Core 1 = 21C.

Orthos Loaded temps: Core 0 = 40C. Core 1 = 37C.

Never gets higher than this. Running Orthos for 11 minutes so far and never goes higher than 40C. Can this be right? If so, I guess I don't need lapping

 

[Comdrpopnfresh]

finished putting everything back together. putting a dab of as5 on the center of the ihs, then twisting the hsf while tightening it is the right thing to do, right? Things look good- with immature paste the system is idling @ the same temperatures it used to. except now the room is 90 degrees instead of 60, so I'd say that did the trick. In 10 days I'll decide if its worthwhile to lap or not...

 

[swtethan]

LAP LAP LAP LAP LAP!


I guess i like having a shingy cpu