[Copper mod] Need some help. :/

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Undertaxxx, Jul 13, 2009.

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  1. Atvaark

    Atvaark Notebook Consultant

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    are you guys talking about the copper heatsink mod for the c90? or just a regular copper heatsink mod?
     
  2. ViciousXUSMC

    ViciousXUSMC Master Viking NBR Reviewer

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    Get some ICD7 and skip all the hard work.
     
  3. Undertaxxx

    Undertaxxx Notebook Consultant

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    i have icD7 actually, applied etc. but i wna max out my cooling possibilities
     
  4. ViciousXUSMC

    ViciousXUSMC Master Viking NBR Reviewer

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    Diamond is thermally better than copper, the ICD7 is thick enough to replace thermal pads. In other words your max cooling capability is with a direct application of ICD and no copper inbetween.

    This is both cheaper and easier, and will provide equal or better results.

    I have replaced every thermal pad on both of my 4870 cards with pure ICD and have had no ill effects.
     
  5. 0.0

    0.0 Notebook Consultant

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    I've been wondering about using a thick coat of ICD7 to replace thermal pads on my one-piece heatsink which covers the CPU / Northbridge / GPU and a couple of capacitors, all thermal pads except the CPU. Although diamond 7 should be a better thermal conductor my main worry is creeping on the thicker servings but if you have found that not to be the case I will go ahead with it.

    +1 rep.
     
  6. Undertaxxx

    Undertaxxx Notebook Consultant

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    I'll just leave it as it is now then, i still got my copper plates tho. lol
     
  7. K-TRON

    K-TRON Hi, I'm Jimmy Diesel ^_^

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    This may be true, but you are missing a crucial part.
    The parts interfacing are a silicon chip, and a copper heatsink. The efficiency of the thermal transfer will be as great as the end material. Since the heatsink is copper and not diamond, regardless of whether you have a diamond or copper interface, the temperature difference will not differ. Diamond may be able to conduct better, but the differences will only be seen if you are using a diamond heatsink.

    K-TRON
     
  8. 0.0

    0.0 Notebook Consultant

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    I'd have to disagree with that as thermal transfer is a product of thermal conductivity.

    For example

    We have a semiconductor that has a junction to case thermal resistance of 1C/W and a heatsink with a thermal resistance of 3C/W.

    Now if the TIM (thermal interface material) has a resistance of 0.5C/W then the total thermal resistance will hopefully be somewhere around 1 + 3 + 0.5 = 4.5C/W. Assuming 10W of power and 20C ambient temperature we can calculate the junction (core) temperature to be 10 x 4.5 + 20 = 65C.

    If our TIM has better thermal characteristics for example 0.1C/W instead of 0.5C/W then for the same conditions our junction (core) temperature would be 61C.

    To make it simpler, if our TIM has a thermal resistance of 0.5C/W then at 30W we can expect 15C on top of everything else. If it has a thermal resistance of 0.1C/W then at 30W we can expect 3C on top of everything else. In other words a core difference of 12C at 30W.

    IMHO if the TIM produces 2C or less at the full rated power then at say 40W if it is 0.05C/W then it wont make that much difference using something much better, say 0.001/C/W for instance.
     
  9. 0.0

    0.0 Notebook Consultant

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    I went ahead with the Diamond 7 and it seems to be working okay. The stuff was a bit runnier than I was expecting but perhaps that's because my room temperature is over 30C.

    [​IMG]
    These readings are based on a room temperature of 32C.


    With all the changes I kept making I don't seem to have a direct comparison to temperatures before but the cpu is probably running 5-10C cooler. Sorry, I got a bit distracted with my cpu core temps as they seemed to be reading too low. After removing the system board I powered it up with external monitor and USB keyboard/mouse, booted windows and set max cpu to basically 3.0 multi (SLFM at 6.0x). Then after waiting for things too cool down, carefully removed the heatsink and with a thermal gun read the case temps. The GPU core steadily climbed to 69C and the case temps matched it almost perfectly however the cpu core temps were a good 6C less than the case temps whereas they should be equal or higher. IIRC I came across semi-vague articles that seem to indicate the DTS can not be relied on below 40C and is only accurate when over 80C. I guess as it is meant for thermal protection it is sort of understandable. I was hoping to push it up to 80C but rushed it too much and had a shutdown. Seemed like too much trouble at the time to re-attach the heatsink and try again so I only got as far as 57C case temp with cores reading 51C. The ACPI temperature reading (THRM) seemed to follow the case temps degree for degree, I wonder if this is a better temp reading to use for the cpu?

    The GPU now runs cooler overclocked than it did on stock with the thermal pad. Overclocked before was 47C above ambient and now is 36C above ambient so a good result there.

    I feel that perhaps the copper mod would do just as good a job, certainly got to be better than those pads ;)
     
  10. Undertaxxx

    Undertaxxx Notebook Consultant

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    Sorry for reviving this topic, but since I ordered my HD4650, I'm searching in doing the mod. The core of the 4650 is shorter then my 9500M gs, so I'll have to 'fill' the gap in between the core and heatsink by doing this 'copper-mod'.

    I heard "K-TRON" used to sell ready-to-place copper plates for this?
     
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