Delidded my i7-3770K, loaded temperatures drop by 20°C at 4.7GHz

Discussion in 'CPUs and Overclocking' started by Idontcare, Aug 3, 2012.

  1. Idontcare

    Idontcare Elite Member

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    I have not seen NT-H1 do that, and I've used NT-H1 in situations all the way up to 105°C.

    There isn't anything special about sitting on the CPU die when it comes to temperature, so I am surprised you observed the separation.

    I wonder if you have a potentially bad tube of NT-H1? Is it old? (>6 months)

    Long ago, like 4yrs ago, I had a 2yr old tube of AS5 that had separated on me from sitting on the shelf for so long. I went to put some on my IHS and a bunch of liquid squirted out, reminded me of when I don't shake ketchup bottle when it has been sitting for a while.

    But after 2yrs I imagine just about any TIM will separate under the influence of gravity as these pastes are all emulsions. That doesn't explain why yours separates in a matter of months and after application, head-scratcher there.
     
  2. Ferzerp

    Ferzerp Diamond Member

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    There was a bit of liquid that came out when I squirt it initially (but my AS5 does that as well, just a little less).

    It may be a bad tube then. I bought it off Amazon back in May. It was Amazon direct and not a 3rd party (or even a 3rd party fulfilled via amazon), but stranger things have happened. Maybe I'll get brave and get a metallic one. The instability of my TIM under my IHS is why I haven't put my second application of IX between the IHS and the H100 block yet.
     
  3. HondaCop

    HondaCop Member

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    Since we are on the subject of TIMs, let me tell you that if you plan on using Liquid Metal Ultra, make sure you don't plan on messing around with your setup in a long time, unless you want to re-lap your IHS and heatsink everytime you take it apart.

    I had my LMU on for a week and after taking it apart, I had to re-lap both the IHS and heatsink. If you don't, then when you attempt to put LMU on again, it will not adhere to the surface. You will keep working it in with the little brush but it will just stay in one place.

    Just a heads up, folks. Use LMU, prepare to re-lap each time you take it apart.
     
  4. Idontcare

    Idontcare Elite Member

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    Hi AtenRa,

    Here are the results, for reference please see this post of mine regarding some questions I had.

    [​IMG]

    For 3.8GHz I kept the Vcc the same for both processors, obviously way more voltage than necessary for the 3770k and the temps show it.

    For 3.9GHz I used the optimal voltage for both processors, which reflects in the operating temperatures and power consumption numbers.

    It was interesting to run these tests because one thing I learned is just how bad, truly awful, the stock HSF is. Consider these results, with the IB delidded and CPU TIM replaced but I then bolted the stock HSF onto it the temps hardly improved at all over those observed before I delidded the CPU.

    Delidding the CPU appears to only help if you also replace the stock HSF with something that can take advantage of the improved thermal conductance.
     
  5. AtenRa

    AtenRa Lifer

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    Hello IDC,

    Thx for the reply and the tests.

    Actually i wanted to see at default settings for both CPUs, default voltages and frequencies (turbo on) on both processors. But its ok, the more data we have the better to understand how those two CPUs behave.

    Taken the data at 3,9GHz that closer resemblance the default settings of the CPUs (voltages), i will conclude that Ivy is cooler than SB with the better TIM and it would have even lower temps if it was soldered like SB is.

    Higher voltages seams to have more thermal impact on Ivy than SB and that could be due to two factors.
    First is Intel's Tri-Gate transistors, they are designed for lower voltage operation. Increasing voltages above 1,1V may dramatically increase current (I) and thus temperature.

    http://www.anandtech.com/show/5763/undervolting-and-overclocking-on-ivy-bridge
    [​IMG]

    This is the reason i have asked to test at default settings (at or bellow 1.1v for Ivy), because of the difference in transistor design and electrical characteristics, testing at same voltages above 1.1v will only make things worst for processors with Tri-Gate transistors.

    The second factor is the smaller die size that creates warmer hot spots. Increasing Voltages elevates hot spot temperatures only making things worst and the default cooling solution (TIM, Heat-Sink Fan) is not adequate for that.

    As a conclusion, i could say that Tri-Gate mechanical (shape of fins) and electrical (V and I) characteristics have bigger impact in thermal behavior of Ivy than die size.

    http://www.chipworks.com/en/technic...4/intel’s-22-nm-tri-gate-transistors-exposed/

    [​IMG]

    [​IMG]

    [​IMG]

    If you remove the IHS, the die size importance in thermal characteristics will elevate due to non uniform power maps created on the die surface. The IHS plays a big role eliminating the non uniform power map.
     
  6. Akantus

    Akantus Member

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    I would say, this could be true, if you were running w/o heatsink. But if you install heatsink on top of bare die it will act exactly as IHS, only the temps will be better, because it doesn't have to go through two more layers of "insulation" (tim under IHS and IHS itself).
    Unless there are big differences between materials of IHS and HSF - e.g. copper and wood. :eek:
     
  7. Plimogz

    Plimogz Senior member

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    I'd expect that the IHS definitely has practical thermal advantages when using the all aluminum heatsinks that are commonly packaged with lower price/TDP parts. And coupled with the physical protection it affords the die from improper or heavy handed installation, I would guess that it makes good economic sense for both manufacturers to prefer installing them, even on SKU's that are bundled with better heatsinks which already have a copper base or slug installed to serve the same purpose as the IHS's name suggests.
     
  8. Ferzerp

    Ferzerp Diamond Member

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    Correct. If IHS with paste helped cooling at all, then why not just stack IHS and make it IHSs all the way down. Absurd, yes, but it points out that flaw in thinking. If 1 IHS helps, 10 would help a whole lot... Of course, an IHS doesn't help. It's a convenience and durability thing.

    *IHS can help if soldered on, but not with paste. The only reason this is the case is the much lower thermal resistance of the solder used paste. If you could solder the heatsink/waterblock on to the die, performance would be even better. Given equal TIMs, an IHS is always a cooling detriment, not a benefit because it forces you to create two areas of high resistance (layers of TIM) than just one (one layer of TIM)
     
    #233 Ferzerp, Aug 13, 2012
    Last edited: Aug 13, 2012
  9. AtenRa

    AtenRa Lifer

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    That is correct, the IHS was made in order for a more economical cooling solution like the Intel default CPU coolers. You would need a much bigger and more expensive heat-sink to get the same results without the IHS.
     
  10. Akantus

    Akantus Member

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    Not sure about that.
    Thermal conductivity of copper is ~400 W/(m·K), aluminum is ~250 W/(m·K). For example cured AS5 (whis is better than what intel uses in IB) is 8.7 W/(m·K), so really IHS is mainly just about protecting the die.

    IHS could help with heat dissipation if you had improperly installed heatsink (one pin not pushed, so it isn't sitting even), where bare die would hit thermal limits almost instantly.
     
  11. Denithor

    Denithor Diamond Member

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    This. Except in that one case (improperly attached HSF) the IHS actually slows the transfer of heat out of the core because you have to use TIM which is much, much less efficient than metal at passing through the heat to the HSF.

    Direct contact of a copper HSF to the die is the optimal situation for cooling. Next best would be die->solder->IHS->solder/liquid metal TIM->HSF. The best we can expect with IB while using the IHS is die->LM->IHS->LM->HSF.
     
  12. artvscommerce

    artvscommerce Golden Member

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    thank you for posting this. really great info
     
  13. BonzaiDuck

    BonzaiDuck Lifer

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    I hope to see more; I could bet that I will, since there was work-in-progress and the OP has proven to be better than his word. But just in case, I've bookmarked this thread for future reference.
     
  14. Idontcare

    Idontcare Elite Member

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    Yeah more is coming, right now I'm working on constructing the 0.2mm thick metal shim so we can generate the right kind of apples-to-apples data for comparison to the stock CPU TIM.
     
  15. BonzaiDuck

    BonzaiDuck Lifer

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    I see your point about that. That's a pretty thin wafer of metal. I guess you could almost call it "foil" . . . .
     
  16. Ferzerp

    Ferzerp Diamond Member

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    What I would like is an IHS that instead of being open and flat, actually made contact with the sides of the die too. Something that had a die shaped notch in it, and touched the die from all 5 sides. Sure, you couldn't do much with this as the die doesn't stick up very far, and there is that rim of whatever material around it, but every little bit helps, right?

    Or since there is nothing conductive in there, fill it up with liquid metal, and seal the IHS down.
     
  17. BonzaiDuck

    BonzaiDuck Lifer

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    I was thinking you could stuff it with diamond paste instead of the liquid metal concoctions. I'm just not sure that it would improve anything: it would only increase the area of contact by an area of 1/8" x 2L x 2W. Those surfaces may not radiate nearly as much heat as the flat surface.

    Best to focus on the contact with the IHS or HSF-base, and the TIMs used.
     
  18. Phil L

    Phil L Member

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    200 um is very close to 8 mil (i.e. 8 thousandths of an inch, or 203.2 um), and you can buy shim stocks of various thickness and different materials (copper, steel, stainless steel, aluminum, titanium, and so on). You can buy a uniform thickness roll (typically in 6" x 50" or 15.24 cm x 127 cm), or an assortment of shim stock package (multiple sheets of different thickness, at 6" x 12" or 15.24 cm x 30.48 cm size). Of course in either case you'll end up with far more shim stock then you would ever need for just cpu shimming, but it's an option if you want to explore it.

    Just a thought,
     
  19. muk1604

    muk1604 Junior Member

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    too temptiong
     
  20. Idontcare

    Idontcare Elite Member

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    Oh yeah, you and yottabit must have great minds that think alike :thumbsup: Based on yottabit's earlier, but essentially identical, tip regarding the shim stock, I previously purchased some.

    It is here already, actually, and I've given it a go once already to make a shim template but the shim stock is very soft and bendy. It reminds me of really really thick aluminum foil. Cuts easily with a pair of scissors. (I did confirm it it 0.20mm shim with my digital calipers)

    So today I will make another, gentler, attempt. LOL @ me, I assumed this stuff was going to be really arduous like the steel stock we worked with in college so I started out with a hack saw :eek: Imagine a hack saw on aluminum foil - shredded mess ensues - and that pretty much captures what happened for me with the first attempt at making my IHS shim.
     
  21. PlasmaBomb

    PlasmaBomb Lifer

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    ^LOL well done IDC.
     
  22. Rvenger

    Rvenger Elite Member <br> Super Moderator <br> Video Cards
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    IDC and Ferzerp. Found this over at HardOCP.





    Quote:
    Originally Posted by ocbaud [​IMG]
    a huge problem i'm having after doing this to my 3570k @ 4.5ghz

    using noctura paste on the core and the IHS with good water cooling.

    After first doing this, i get temps idling around 31c-32c on all cores.
    Load temps with intel burn test would show 62c max on any given core.

    after a few weeks of this computer running almost 24/7 (not under load, mostly idle)
    I get the same idle temps, but load temps hit 90c on a couple cores(i stop IBT before it goes on longer than a couple seconds)

    this has happened 3 times now and each time, after i pull the ihs off and replace the thermal paste, the temps come down again.

    it makes great contact at first, but given enough time it stops working well.

    what could i be doing wrong?
     
  23. BonzaiDuck

    BonzaiDuck Lifer

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    How is the Noctua TIM more of a grease than a paste? The original Intel stuff that IDontCare shows looks like stiff putty. I think somebody on the HardOCP forum mentioned IC Diamond, which is already like stiff cement or putty, and dries out. The diamond stuff doesn't flow, though.
     
  24. Idontcare

    Idontcare Elite Member

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    I don't discount it, I believe it. What I take from this is that NT-H1 is simply incompatible with the thermomechanical environment that exists in direct-die applications.

    For example we know the mismatch in coefficients of thermal expansion will be much larger between that of the silicon Die and the metal IHS versus that which exists between a metal IHS and the metal base of an attached HSF/water-block.

    Additionally we know the wettability of the silicon die is markedly different than that of the metal surfaces for which NT-H1 was developed to adhere to. This makes issues of viscosity and surface adhesion a factor when matters of thermomechanical forces are a concern, which they are.

    So what does this boil down to in terms of why NT-H1 could be giving rise to these results? Two things can be happening, and possibly in combination.

    One is the push-pull pumping effect that comes with the mechanical expansion and contraction of the silicon, the TIM, and the overhead IHS. Eventually, given time, the TIM itself will be squeezed out of the gap that it occupies between the die and the IHS and an air gap will be left in its place. The air gap most likely forms when the CPU cools down.

    [​IMG]

    Then when the CPU heats back up, the air gap prevents the IHS from heating up in concert with the die and the TIM, resulting in an IHS that is not expanding to fill in the air gap, leaving the CPU much hotter than before.

    The second point of concern is that of emulsion separation - the molecular components that comprise NT-H1 may experience separation at the behest of the silicon die interaction (it will actually be a silicon nitride at the surface). NT-H1 was probably not designed to remain an emulsion when in contact with silicon as it was designed to remain an emulsion when in contact with copper, aluminum, or nickle (more specifically, the metal oxides of those elements).

    So a chemical separation may be the culprit as well, and likely it is a combination of both.

    If it is just chemical separation then choosing a different TIM will be the solution.

    If it is is thermomechanical push-pump that is the culprit then going with the more permanent metal-TIMs (Indigo Xtreme or Liquid Ultra) would be the solution.

    In either case, going with the more permanent metal-TIMs would appear to be the one-size-fits-all solution provided the thermomechanical stresses that will then arise from having the mismatch in coefficients thermal expansion do not cause issues for the IB packaging itself (ala bumpgate dejavu).
     
  25. BonzaiDuck

    BonzaiDuck Lifer

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    I figured that if you spent the $25-bucks, you're going to try the diamond stuff? One wonders if that would leave a stable result . . .