i7 Lapping Mini Guide

Discussion in 'Modding Worklogs' started by Trucrymz, Nov 14, 2009.

  1. v81

    v81 Member

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    I rekon I'll give this a go on my Q6600.
    Am getting 80c temps at 3.2GHz with a thermalright XP90c cooler and low RPM 90mm fan.
    (Thats with 22c ambient running Intel Burn test)

    With a lap, both on CPU and HSF, plus a higher CFM fan and new application of AS5 i might get it sorted.

    Any before and after results on temps?
    Other laps I've seen have shown only a mild improvement.
     
    Last edited: Nov 16, 2009
  2. ford ftw

    ford ftw Member

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    Nice guide looks good.
     
  3. PHAT_pudding

    PHAT_pudding Member

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    my Q6600 is lapped, has been for a year and a half :)

    I tested the CPU before lapping it in an open air environment on idle (bios screen) for 30 minutes with stock cooling and AS5. then took it out and lapped it to a shinyness achieved by 800 grit paper. then put it back in under exact same conditions (steady air conditioned room), ran in bios for another half hour, and it shaved 4 degrees off.

    would have liked to know what its like under load :( but i was too hasty to lap it.

    and there hasn't been any corrosion issues on the CPU, but around the waterblock i have some oxidation of the copper which isn't in contact with the CPU. The thermal paste basically stops the corrosion on the CPU heat spreader.
     
  4. sogens

    sogens New Member

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    why don't intel and friends make them so this doesn't need to be done? seems a bit silly to me
     
  5. HunterBunter

    HunterBunter Member

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    probably because of the extra time and effort required to machine every cpu, plus the temp gains are more useful when overclocking, which they don't massively care about.
     
  6. STUdog

    STUdog Member

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    This is my lapped Q9550,

    Main issues were is that one core was always cooler than the rest. Core 0 was about 5deg cooler at idle and 10deg cooler at load.

    I know lapping prob wont fix this as its prob a stuck sensor but just wanted to see if this helps.

    Well here are some pics, let me know what u think

    I used 400, 800, 1200 grit wet and dry and brasso at the end which is a metal polisher.

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Took about 2 hours to do the job.

    Havent put the cpu back in yet but will let you know how the temps are.


    Cheers

    STUdog
     
  7. futurikon

    futurikon Member

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    Mass production imperfections. If intel spent money getting every CPU perfectly flat we'd be paying more for them no doubt. 95% of those who buy the chips wouldn't even benefit either.
     
  8. futurikon

    futurikon Member

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    Great job STUdog! Looks mint, hopefully it performs as good as it looks ;)
     
  9. STUdog

    STUdog Member

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    Cheers, Thanks buddy
     
  10. OP
    OP
    Trucrymz

    Trucrymz (Banned or Deleted)

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    Thanks for the tips. I was thinking about the oil but worried about it getting under the heatspreader. Maybe I'll try it next time :) I used the figure 8 technique on one of my other chips, and I found it useful for really smoothing out and getting rid of the 'scratch' marks. I didnt use it did time cos I had 2000 grit paper. and for me, I find it easier to not apply downward pressure when going straight forward & backwards.


    I think you will get a siginficant improvement if you lap both your Q6600 and your XP90. I did it to my Q6600 and a Thermalright IFX-14 and got close to a 10 degree drop off my load temps. I'll post some temperature results after I lapp my waterblock.


    Thanks.


    Great job. Looks really good! Im sure your temps will improve, especially the cores that are hotter. Lapping will almost always decrease the differences between each core. My only concern is that, I have read that brasso (and other polishing agents) will leave a thin film behind that will interfere with the thermal transfer.

    Thanks for all the comments guys!
     
    Last edited: Nov 16, 2009
  11. TMM

    TMM Member

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    I think he means that, if you do not hold the CPU perfectly level as you sand, you will unnecessarily sand down the edges. It is impossible to hold it perfectly level by hand and apply level pressure. That's why people use the figure 8 method and rotate it 90º to even out any bias in the pressure they apply the CPU.

    From your pics it looks like your heatspreader was convex rather then concave.
     
  12. LuciferDarklord

    LuciferDarklord Member

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    Hey Trucrymz, did you lap it on the glass coffee table in your pic? Not trying to nit pick or anything - but the glass on them is 'suspended' from the corners which will give you an ever so slightly curved surface. Not trying to be a dick but might help on further attempts if the glass is on something perfectly flat (pool table?). I'm only mentioning it coz in your pic I can see shit under the glass, like pliers etc.

    Hey you know you can also use toothpaste as a very fine lapping paste (straight on the glass) it has very fine abrasive particles in it - i dunno aluminium oxide or something like that
     
    Last edited: Nov 16, 2009
  13. OP
    OP
    Trucrymz

    Trucrymz (Banned or Deleted)

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    Thanks for the heads up. I never knew about the toothpaste/alu oxide. That's interesting, would save you from having to find those hard to find, fine grit papers above 1200 or above 2000 even

    The glass surface I used is actually a HiFi rack that has multiple shelves. Its supported on the corners as well as having a frame around the sides. I probably can do better, maybe next time I will buy a small mirror/glass etc

    Thanks, I understand. As described in the guide, I did take measures to minimize any bias, and as I said, I used a razor blade to check the heatspreader before lapping. and again, for the chip to be convex, the centre needs to be higher than the sides, which wasnt the case. And even if it was convex, I'd prefer a flat heatspreader over a convex one anyway.
     
    Last edited: Nov 16, 2009
  14. cvidler

    cvidler Member

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    I think you'll find thermal transfer is an exact science. It's well understood, and numerous people and scientists make their living from it.

    And for those that think you're smarter the the guys at Intel, the IHS flatness (or lack thereof) is an important design feature. Relating to more than just heat transfer (pin contact, and solder joint stability being two).

    from the Q6xxx and Q9xxxx doco.
    So by removing material from the IHS, you're reducing the preload of the heatsink. Potentially creating early failure of the solder joints in the socket.
     
  15. OP
    OP
    Trucrymz

    Trucrymz (Banned or Deleted)

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    I obviously wasnt talking about thermal transfer, I was talking about what grit you need to lapp up to. It would had been much easier to sound smart after you have read and understood what we are talking about

    And noone is trying to say they are smarter than Intel engineers when they lapp their CPUs. Its obvious there are cons to lapping your CPU, but Despite whatever reasons Intel designs their heatspreaders the way they do, the bottom line is that, its been proven time and time again that lapping does increase the thermal transfer efficiency, and for many that benefit outweighs the cons.
     
    Last edited: Nov 17, 2009
  16. Voltus

    Voltus Member

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    I cant believe theres so many ppl trying to have a stab at u for this guide..

    I like shiny!

    nice guide.
     
  17. HyDrA

    HyDrA Member

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    Yeah, what is with people having a stab? Lapping your CPU used to be the norm 5-6 years ago to get that extra overclock!

    I've been considering doing this to me Q9400, which seems to always be hotter on one core by several degrees.
     
  18. OP
    OP
    Trucrymz

    Trucrymz (Banned or Deleted)

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    Thanks for the positive comments guys. Im a little shocked at how ignorant some people are, especially on a forum like this, which has so many incredibly knowledgeable people...(as well as a wealth of knowledge for everyone else) Of course its the many different opinions that make these forums so great... its only when the opinion is based on rubbish that it starts to annoy ...
     
    Last edited: Nov 17, 2009
  19. futurikon

    futurikon Member

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    I liked your guide, forget about the other nay sayers :p
     
  20. v81

    v81 Member

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    With a window of 18lbf - 70lbf i doubt shaving half a millimeter off an IHS is going to cause any issue.

    As far as the intel docs go lapping is probably trivial compared to some of the 3rd party sinks, and methods used to attach them.

    The vibe i'm getting from you is that your against this idea, and to be against an idea like this on OCAU is like walking into a church and pushing atheism.

    We fuck around with hardware here on OCAU, some ideas are good, some bad.
    Some work and some don't.
    And from time to time something gets blown up.

    After all, experimenting and bending the manufactures rules and specs is what OCAU is about isn't it?
     
    Last edited: Nov 17, 2009

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