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finished lapping my Q6600 (with pics and results) - Page 2

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October 22, 2007 8:02:34 PM

razor512 said:
cool, when you were lapping the CPU, did the surface get hot?

when i lapped my heatsink i just kept the sandpaper on a flat surface and
and went crazy moving it up and down the paper really fast, going to higher grits to get a mirror finish but the surface was also really hot when i was done (which is why i didnt do it to my cpu)


No it didn't get hot. I'd discourage anyone from lapping to the point of the surfaces getting hot... not because the friction generated heat is bad, but because you probably aren't getting a nice flat lap by moving that fast. The key is slow, precise movements. Also, you can lap your CPU with no fear of the friction you're generating hurting it; after all, how hot does your chip get from CPU load? My Q6600 can hit 65 °C depending on the settings I'm using which is probably much hotter than it gets when I lapped it!
October 22, 2007 8:56:44 PM

Is there such a thing as lapping the CPU or HSF too much?
October 22, 2007 9:19:12 PM

stabgotham said:
Is there such a thing as lapping the CPU or HSF too much?



yep, if you start seeing come of the chip through a hole made in the heat spreader then you know you sanded it too much :) 

when lapping, your not really looking to make it super thin, your just looking to make it as flat and smooth as possible.


(i wonder why don't they just give the heatsink and cpu a smooth finish to begin with)

PS when it comes with some AMD stock coolers, lapping it is vital for overclocking

here is why you should give your amd heatsink a smooth finish

(large image, click for full view )



here is a amd stock heatsink when placed on a scanner
Related resources
October 23, 2007 4:17:56 AM

holy crap. I was thinking of giving this a shot on my next build, but after seeing that pic, maybe I should lap my current 3700+ with my stock HSF. If I try, I guess the best method is to sand a little, look at it, sand a little more, look at it..., making sure you don't do it too much. Very interesting topic.
October 23, 2007 4:20:41 AM

Also, I've read some of the other guides on how to go about lapping. Some talk about doing this vertically rotating 180 or 90 degrees every few minutes to make sure you sand evenly. My best guess is that the figure-8 method does the same task without all the shifting and turning....right?
October 23, 2007 6:17:10 AM

Maybe I'm not all that 'knowledgeable' on lapping but...

Does everyone 'lap' off their nickel plating? You know why that plating is there, right? Because copper corrodes in the presence of Oxygen.. even the airborne oxygen..... You might say 'it won't be exposed to Oxygen". but my comment would be 'yes it will... oxygen will diffuse into the thermal paste'. Any around that has lapped their CPU a year+ ago and can comment on what their CPU looks like now?

The only thing stopping me from lapping my CPU is the corrosion problem.
October 23, 2007 6:53:37 AM

cyberjock said:
Maybe I'm not all that 'knowledgeable' on lapping but...

Does everyone 'lap' off their nickel plating? You know why that plating is there, right? Because copper corrodes in the presence of Oxygen.. even the airborne oxygen..... You might say 'it won't be exposed to Oxygen". but my comment would be 'yes it will... oxygen will diffuse into the thermal paste'. Any around that has lapped their CPU a year+ ago and can comment on what their CPU looks like now?

The only thing stopping me from lapping my CPU is the corrosion problem.


I dought after two years theres going to be soo much corrosion that it will affect the cooling, show me proof that after two years it will affect cooling. Aren't we nit picking here a little?
October 23, 2007 2:21:21 PM

not all copper has this problem, and if it doesn't it may take longer than 2 years, not sure if this is true for the CPU but My mom has some pots and pans that are copper and it has been years and they still look almost new


probably for the CPU, the damage to the copper will probably take like 5-6 years and by then you will most likely have upgraded

generally lapping surface of the heat spreader on the CPU is smooth but the shape can be a little distorted which can cause higher temperatures

(I will scan a high res image of the surface of the heat spreader on the heatsink)
October 23, 2007 4:27:06 PM

shiny = smoother = flatter = better contact. said:
shiny = smoother = flatter = better contact.
Just to clarify:
  • smoother does not always = flatter* (a chromed ball bearing is very smooth and shiny, but is far from flat) and
  • flatter does not always = better contact UNLESS BOTH mating surfaces are "flatter".
    The ultimate goal in lapping is to get both HSF and IHS to mate perfectly. This can be done with any shape profile**, but it is incredibley more difficult to create mating shaped profiles than it is to simply make both surfaces flat. So you want both your HSF and IHS to be smooth AND flat for better contact. The glass/mirror provides a flat surface***, and you use progressively high grit sandpaper it make it smooth.

    The reason you really need to lap both HSF and IHS is to get the two surfaces mated (i.e. exactly the same shape). It's very possible to increase your temps by only lapping one of the two (as in the case of the TR U-120, which has been designed to better mate the concave IHS) because you could detrimentally effect the surface match.


    * - flatter DOES = smoother, though, because the flatter a surface becomes, the smaller the "bumps" become and the smoother it becomes (which also makes it shiny).

    ** - as mentioned above, that's why the people at TR make the U-120/Extreme with a slightly rounded bottom, they are trying to mate the HS to the IHS because the IHS is not flat.

    *** - if you're REALLY fanatic about a flat surface, you can get granite surface plates that are manufactured to have very flat surfaces (within one ten-thousanth of an inch). I'm not suggesting you buy one (they're rather expensive) but if you ask around you machinist friends, you might find someone that has one you could access. Just thought you might like to know. 8-)
    October 23, 2007 5:07:56 PM

    I thought to myself that if I'm going to lap my HSF then why not do the CPU to. It doesn't make since to only do one.
    October 24, 2007 8:27:33 AM

    systemlord said:
    I thought to myself that if I'm going to lap my HSF then why not do the CPU to. It doesn't make since to only do one.


    Very true. You're talking about two surfaces mating to form a thermal transfer. Doing just one is kinda silly; you need to do both halves!
    October 24, 2007 2:19:54 PM

    I only did the heatsink on my main pc (stock cooler was really bumpy like the image I posted)

    so i sanded that to a smooth finish and I got around a 3-4C reduction in temperature,
    October 24, 2007 4:09:32 PM

    AutoZone, Advance Auto Parts, and the like. Call ahead and ask what grits of refinishing (car paint) sandpaper they have. I got 400, 800, 1000, and 2000 at a local Advance.
    a c 121 K Overclocking
    October 24, 2007 4:41:50 PM

    A very nice post. Good pics and explanation. I am now confused,though, because I just read another post where a thermalright extreme ultra 120 reviewer found a convex heat sink, but after lapping both the cpu and the heat sink, got no improvement. http://www.cryo-laboratory.com/forums/reviews-guides/67...
    Is there some explanation?
    October 24, 2007 11:56:13 PM

    Dunno what to say about that link...
    November 7, 2007 8:28:44 PM

    Interestingly, after lapping and such (razorblade test shows it's flat as can be), while all cores dropped substantially thus far, cores 2 and 3 are 2c higher than cores 0 and 1 under prime95 load.

    I'm thinking maybe I should reapply the AS5 maybe my line wasn't long enough.

    Zalman 9700, 3240mhz right now, 49, 47, 51, 51 after an hour of Prime. Can't complain :)  1.35v I plan to go for 3.6 at least though which is why I'm lapping, etc. now. 3240 is just the "burn-in" speed.

    I did notice the Zalman is seemingly a bit convex, at least the outer edges are a bit higher than the center area (using the razorblade test, and we're only talking about a human hair higher--just a sliver if light comes through), but since the chip doesn't cover the entire base of it, I am thinking that if ANY heatsink was pre-lapped and not in need of a lapping, it would be that one. For all I know the part that actually makes contact with the IHS could be bear perfect (it's certainly machined better than most other HS's I've ever seen before).... so I dunno.

    I did a test where I installed the heatsink, waited a few mins then removed it... the grease was spread very evenly. Then I cleaned everything and reapplied the grease to the IHS and re-installed.
    November 7, 2007 8:55:33 PM

    It settled down a LOT after another hour... 44c straight across :)  Couldn't be happier. It probably is just taking a bit for the grease to finish spreading.

    If anyone out there is on the fence about lapping, DO IT. I've dropped about 8c already and I haven't even begun to "cure" yet!
    November 7, 2007 9:07:56 PM

    NICE!
    November 8, 2007 12:32:45 PM

    intresting points... maybe once my CPU is out of warranty I will do the same... although I'm leery of recking my nice Zalman 9700nt finish


    razor512 said:
    not all copper has this problem, and if it doesn't it may take longer than 2 years, not sure if this is true for the CPU but My mom has some pots and pans that are copper and it has been years and they still look almost new....


    how is this possible?!?! after I used my copper pot/pans for the 1st time they were tarnished lol... then again it could be I have a gas range...
    November 8, 2007 1:56:41 PM

    After you guys lap the sink/processor, you don't apply thermal paste?
    November 8, 2007 2:43:05 PM

    yes you still have to apply TIM but less is required with better results
    November 21, 2007 9:06:19 AM

    marlborosmoker said:
    shiny = smoother = flatter = better contact. It's fairly simple concept. The CPU wasn't flat therefore there wasn't a good transfer of heat. With anything mass produced there will be slight variances.

    at a microscopic level it will look like this if its not shiny. /\/\/\/\/\/\/\/\/
    Note there are less points of contact as opposed to a surface like this ____________


    Actually it's exactly the opposite, if both surfaces were like this:
    /\/\/\/\/\/\/\/\/
    /\/\/\/\/\/\/\/\/

    You would have a much bigger area of contact and better heat transfer. The problem is that creating surfaces that "match" is not trivial, as such it seems we are "stuck" with flat for now.

    I think it was IBM that registered or applied for a patent about making "jagged" heatsinks, to increase contact area.
    November 22, 2007 8:58:31 AM

    @spirer - think machining a microscopic surface if you're talking about would be very difficult considering you'd need to do it on both components. Also think what would happen to it if you rubbed them together (likely you'd destroy them). For now, flat is king :) 
    December 18, 2007 11:04:35 PM

    Actually the best way is to solder the heatsink into the cpu...
    December 20, 2007 7:20:40 PM

    i did this once on a motor, on a car trip, when my
    parents were driving and i was trying to get max
    performance out of that motor.

    questions~
    what were the total hours & dollars for the project ?

    the heat sink (in the other thread) - did you
    get a flatness measurement before lapping it ?

    it sounds like it might be a bit of a physical
    workout.
    Anonymous
    December 29, 2007 6:26:09 PM

    Nice
    December 31, 2007 4:08:05 PM

    I idle at about 35-36 (stock speed) on my Q6600 B3 stepping. If I lap my processor and thermalright ultra 120 extreme, would i be able to drop my idle to high 20's or really low 30's?
    January 4, 2008 5:43:00 AM

    @ The_Gremlin : Are you sure the TR guys made the extreme so courved to match the processor? I've got one of those coolers myself (on an e6600) and I remember vaguely reading somewhere, either here or firingsquad, that the extreme was so uneven because the base plate would flex a bit when the upper and lower part were 'put together' encapsulating the heatpipes.

    @ cyberjock : The copper problem definetly is one, but with electronics like this I hardly think the time-to-live is going to be shorter than the expected lifespan of the processor. I've seen cars with scratched radiators (they're copper too), that still were leak free and more or less in original shape even after being 30 years old - and you can't convince me that no rogue stones would've scratched the protective paint off somewhere over the course of time.
    January 4, 2008 5:45:43 AM

    By the way I haven't lapped either ihs or the tr as I can't afford a new cpu if I ruin it, but if I should decide to upgrade to a q9650 once they're available I may convince myself to take the chance. I'd after all have the old cpu still if all else fails.
    January 24, 2008 5:12:04 AM

    Lapping is easy if you know what to do. I can say I have lapped 3 surfaces in my system. two of them I did without using a lubricant such as dish soap+water (CPU IHS and HSF). I can also say that not using a lubricant was quite a bit harder and seemed to yield less gain. Oh well, I'll try again once I get a new cooler. Hopefully the Hyper 212 Deluxe will beat the TRUE-X when it comes out, I'm crossing my fingers.
    January 24, 2008 2:27:19 PM

    Update: I made a air tunnel from my heatsink (thermalright ultra 120 extreme) to the back of my case. It covers the entire heatsink and sticks out over the fan a little and then pipes the air to an exhaust fan. I was able to get my cpu to idle at 31c and load never above 47c (this is a q6600 b3). I overlocked it to 3GHz and it idles at 37c and load still never over 47c.

    I did not lap, just used cardboard!
    January 24, 2008 11:11:20 PM

    Thats great!, I'm gonna try that next time I buy a new Heatsink, thanks for the advice.
    January 25, 2008 1:47:13 PM

    grieve said:
    Good Job, looks great, I may just do that myself… my q6600 runs hot also.

    On another note :
    I have been trying to figure out how we spend 200-1100 on a CPU and we have to lap the damn thing to get it to perform the way it should outa the box. Is it just me? I really believe that my $100 after market heatsink and my $600 CPU should already be lapped when I get it!

    Perhaps soon well buy new cars with flat tires.


    It does perform the way it "should" out of the box. it "should" run at the speed that they print on that box. My Q6600 hit 2.4Ghz no problems at all with NO LAPPING ant ran at an avg temp of 30 degrees on the stock intel cooler.

    Try to keep in mind what you're doing is gaining EXTRA performance for FREE by pushing your chip beyond the manufacturing tolerances. There is no need for intel to supply us with pre-lapped chips with copper contact areas for them to perform as intended.
    January 26, 2008 5:21:00 AM

    But it sure would be nice. Also related, some HSF manufacturer's are starting to machine their bases to incredible flatness (better than can be achieved by homemade jobs, even with very high grit) evidenced here: http://us.st11.yimg.com/us.st.yimg.com/I/yhst-655562697...

    Source: Petra's Tech Shop (great shop btw)

    Heatsink is a full copper scythe ninja.
    January 28, 2008 11:23:40 AM

    well done
    January 28, 2008 12:42:58 PM

    systemlord said:
    Its so easy a caveman can do it.

    Oh no you didn't!
    January 28, 2008 12:57:36 PM

    rodney_ws said:
    Oh no you didn't!

    I've been wait for this to happen for a while now.
    February 2, 2008 5:53:23 PM

    What about warranty, i guees if you lap your processor than you can say goodbye to the warranty right ?
    February 2, 2008 6:28:19 PM

    goodbye warranty, hello lower temps :hello: 
    a c 225 K Overclocking
    February 2, 2008 9:30:54 PM

    speed6 said:
    What about warranty, i guees if you lap your processor than you can say goodbye to the warranty right ?


    Thats exactly right, If you lapp the CPU your warranty is instantly gone!

    So don't screw it up or at least season it with a little salt and pepper when you eat it! :pt1cable: 
    February 3, 2008 6:48:50 PM

    Is really tricky to get truly flat surfaces are a on both CPU and heatsink when we sand we tend to lean forward and pull back and gives a convex surface and of course the same thing is true on both the CPU and heat sink. You also have a problem of what you're using as a sanding base if you're talking thousand grit paper size of the abrasive particles can be smaller than the distortion of sanding base. It's my opinion that slightly convex surfaces on both heatsink and CPU can be an advantage when pressed together with reasonable force the centers of both complements will come in contact first ensuring the thinnest possible heatsink compound distribution. Another difficulty is maintaining equal force centered directly over the processor cores. From what I've seen little attention is paid to this maybe it's a second-order effect or maybe equal tightening the screws and exact distance on the support structures makes a difference. Just something to consider
    March 11, 2008 4:53:03 PM

    How do you hold your CPU so that it stays flat and so that you don't wreck anything?
    March 12, 2008 1:04:24 PM

    Q6600@3.0mhz,Zalman9700. Peak core temp 44C under Prime95, Idles at 20C'ish.
    With your MB vertical as opposed to flat on a bench the weight of the heatsink/fan/fins pulls the CPU and Cooler surfaces apart, with a twisting/leveraged moment. Big time. The Zalmans height and weight is the worst case for this effect, but it's airflow etc compensates, I believe.The pressure of the clamp is all that keeps things sandwiched tight when vertical, hot, vibrating .....ie. running the fan fast. The pressure of the cooler on the CPU flattens the CPU lid's convexity when clamped real tight (I had to grind Ni plated burrs off the back of the holes on my Zalmans clamp to maximize it's clamping force, and also put the clamp arm vertical, or up/down, not horizontal...you need a bent screwdriver to get it tightened). A very very thin layer of warmed/shaken Zalman grease to both surfaces fills in surface roughness dips nicely... no need to 'lap' at all...in fact removing that nickel plating probably has some negative effects mechanically, thermally and over time chemically too (copper oxides etc). Get your greasing and clamping right...lapping is no solution! Thats my opinion, anyhow.
    March 14, 2008 9:12:41 PM

    when i put in the 120 extreme u didnt have to remove the top fan did u?
    April 2, 2008 7:51:13 PM

    Are you guys kidding here? I find it really hard to believe lapping will drop temps 10 C!!

    Never mind the destroying the warranty for the cpu/cooler. Can somebody show me of a review site showing a benefit of lapping? I haven't seen one website review showing a clear benefit esp. given the risks....

    Show me something from Toms/Anandtech or other reputable site where I can trust the data to be reliable and you'll have me convinced... :)  I would think Thermalright created this cooler convex for a reason, to maximize cooling, their engineers would know all about these issues!

    But hey, if there is some objective evidence, I got some work to do! My rig comes in on Friday and I'll have some work to do. :) 
    a b K Overclocking
    April 2, 2008 8:28:12 PM

    @OP: Nice work [:turpit:2]

    @Everyone: During my experience when you are lapping with 600+ grit, adding a very small amount of shaving cream (i know it sounds crazy, but its true!) will give you a more flatter and shinier surface. I will try to post pics of my lapped E2180 later.

    edit:

    Here is a pic of one of my lappped CPU:
    a b K Overclocking
    April 2, 2008 8:34:24 PM

    dignatec said:
    Are you guys kidding here? I find it really hard to believe lapping will drop temps 10 C!!

    Never mind the destroying the warranty for the cpu/cooler. Can somebody show me of a review site showing a benefit of lapping? I haven't seen one website review showing a clear benefit esp. given the risks....

    Show me something from Toms/Anandtech or other reputable site where I can trust the data to be reliable and you'll have me convinced... :)  I would think Thermalright created this cooler convex for a reason, to maximize cooling, their engineers would know all about these issues!

    But hey, if there is some objective evidence, I got some work to do! My rig comes in on Friday and I'll have some work to do. :) 

    What you have to consider is that even though people at Thermalright would have known about it they would have to find a acceptable "range" to design the HSF around since each CPU is unique. The lapping benefits will differ depending on each CPU. I have personally seen some of these 10C or so temp drops after lapping (esp. on old Prescott CPUs), while other times it is about 2-3C. It all depends on if you want to risk the warranty and get cooler or vice versa. Another factor is the quality of workmanship and the concave/convexness of the CPU.
    April 3, 2008 2:03:50 PM

    Shadow: Thanks for not flaming me, I had a feeling some people might get a bit upset about my remark.

    However, I'm talking bout a modern pc, the q6600. There was one review site that showed no diff (forget which one, can google for it) and that makes sense for me. I agree the TRUE may not be 100% optimized for older chips in terms of modern chips, it should be for newer chips. Again for 2-3 C, it's not worth me spending 3+ hrs for very little gain and losing my warranty....
    April 3, 2008 3:05:57 PM

    systemlord said:
    Its so easy a caveman can do it. My load temps are a lot lower now

    Zip it.
    April 3, 2008 4:52:18 PM

    rodney_ws said:
    Zip it.


    ???
    !