Abit AI7 - Yet another NB failure, but a different question

Discussion in 'Abit' started by Tony, Aug 29, 2004.

  1. Tony

    Tony Guest

    Yes, the stock NB fan on my AI7 is showing signs that it will soon fail. I'm
    in the U.S., so I don't want to go the route of either RMA'ing my board or
    buying the same unreliable fan from Abit. I know most would recommend
    replacing the fan with the Zalman ZM-NB47J. I would certainly consider going
    that route, but I would like to try and find a better fan - with speed
    sensing - that will work with the existing mounting arrangement. Sort of a
    better pop-in replacement for what's already there. Is there any such fan
    out there? If not I will just go with the Zalman, and modify the Registry
    for uGuru to set the min RPM for the NB to zero.
     
    Tony, Aug 29, 2004
    #1
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  2. Tony

    Tony Guest

    Oh, I should also say that I'm using the Zalman Cu7000 on my processor, so
    any NB solution should hopefully not interfere with that.
     
    Tony, Aug 29, 2004
    #2
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  3. "Tony" wrote

    Hi,

    I don't think the blue Zalman NB-cooler can fit the AI7 (or Modern INTEL
    boards in general) as the Zalman uses *push-pins* and the AI7 has
    *Sping-Clips*. The Thermalright NB-1 Chipset Cooler looks to be one of the
    best 3rd party NB-HSF for the INTEl mobos.
     
    Wayne Youngman, Aug 30, 2004
    #3
  4. Tony

    Tony Guest

    Yes, I was afraid of that. While the clips allow for easy replacement, it
    limits the aftermarket options. The NB-1 is about 48mm square. I'll have to
    check to make sure it won't interfere with the Cu7000.

    I've read of some using thermal epoxy to attach the Zalman to the NB chip,
    bypassing the mounting issues.

    Do you have any info on the Vantec IceBerg? That's even bigger than the NB-1
    (!), but seems to sit lower. The only thing that bothers me about it is that
    it does not have a speed sensing fan.
     
    Tony, Aug 30, 2004
    #4
  5. Tony

    kony Guest

    Is the clip on the original 'sink removable (perhaps fan needs
    removed first)? If so, reusing the clip will allow any old 'sink
    with a suitably wide channel down the middle, for example, a
    Pentium 1 heatsink.
    I use thermal epoxy all the time to attach large passive 'sinks
    to a northbridge, but it is not a good idea to do so for a
    flipchip like the 865, because of both the small core having more
    stress, and the increasing thermal density making it more
    important to have best (reasonably possible) thermal interface.
    Traditional thermal compound (even the cheap generic silicone
    goop) far exceeds thermal efficiency of any epoxy.

    You are better off forgetting about speed-sensing fan and looking
    at long term solutions, either a fan that won't be prone to fail
    in another 12 months (high quality dual ball-bearing model with
    low RPM, 15mm or thicker x 40-50mm diameter) or a passive 'sink.
    Fan cooled northbridge is not an intel design and should not be
    needed unless you're trying to squeeze that last dozen MHz of
    overclock out of it, or operating in an extreme condition like
    middle of the desert, but then the REST of the board isn't
    engineered to survive that environment either. Many 865/875
    boards use only a passive, fanless heatsink.
     
    kony, Aug 30, 2004
    #5
  6. Tony

    Tony Guest

    Yes, the clip is removable.
    Which passive sinks have you used on the NB?
    Yes, that what really ticks me off about what Abit did. They did put a fan
    on the NB (of course to squeeze the last bit of oc'ing out of it) and used a
    well designed but cheaply engineered sleeve bearing fan for it. They could
    have gone with a dual ball bearing fan, and it would have added maybe $2 to
    the wholesale cost of the board.

    Anyway, thanks for your comments! Good ones like these help!
     
    Tony, Sep 1, 2004
    #6
  7. Tony

    kony Guest

    Take your pick, I've been at this for a long time, don't need to
    buy any heatsinks because I have several drawers full. Even
    after a system is too old/slow/broken/etc to have core components
    reused, things like 'sinks can be used again to be both lower
    cost and more environmentally friendly. Plus, not too long ago I
    needed some HQ fans and by buying a case of 'sinks with good fans
    already on 'em, I got the needed fans cheaper than if purchased
    separately, so I had even MORE 'sinks to (do "something" with).

    One of my favorites is 1/3 of a Pentium 2 Klamath heatsink
    (passive OEM tall-tined style). Often I'll use an old Pentium 1
    heatsink, or for an extremely overclocked system, I may take a
    'sink wide enough to mount a 50mm fan, like an early socket 370
    or socket 7 'sink, then mount the fan, but not over the
    northbridge 'sink itself, but rather draped over the power
    regulation circuitry.. slow enough to be inaudible and live a
    decade or two. If you use a heatsink with a very flat base, at
    least (roughly) 3mm thick base and tines over it's center (unlike
    those normally placed on motherboards with only a flat area over
    the core center, heat source) it's not very hard to keep a
    northbridge cool enough, the main limit is CPU heatsink
    clearance, and on socket A boards, having enough room to
    manipulate the heatsink clip if the tabs are vertically oriented,
    but that's not a problem for you, your P4 box.

    Aluminum is soft and easy to work with, you can end up with
    whatever shape and size you want if you're willing to hacksaw and
    file for a couple minutes.

    Most of the boards I've done have been long since sold, or still
    running here and can't be disturbed at the moment, but a few
    random motherboards I've lying around unused with epoxied NB
    'sinks:

    http://69.36.189.159/usr_1034/nb_sinks/1.jpg
    http://69.36.189.159/usr_1034/nb_sinks/2.jpg
    http://69.36.189.159/usr_1034/nb_sinks/3.jpg
    http://69.36.189.159/usr_1034/nb_sinks/4.jpg

    The funny thing is that it may've actually cost them MORE to have
    that fancy abit-specific fan made, a decent dual ball-bearing fan
    might've cost a few dimes more if their 'sink was one already in
    production.

    One thing that many manufacturers seem clueless about is that it
    isn't necessarily a desirable goal to have as shallow a fan as
    possible. Indeed now they may have the 'sink sticking further up
    in the air than the fan, when a fan must be 15mm thick or more to
    allow for dual ball bearings of suitable size. Another problem
    is that they don't seem to grasp that a fan does not need to spin
    at 3500+ RPM, indeed if it isn't sufficient at 1500 RPM they have
    used an incredibly poor heatsink, or sadly enough, may simply
    have used one with a very poor surface finish (it seems that the
    tops and sides of these 'sinks look mighty pretty but the
    business end, the only side actually needing to be smooth, is the
    roughest quite often)... then to top it off many of those on
    non-flipchips don't even touch the core except on the outer
    edges.


    Perhaps the worse is when they use a single ball bearing, because
    a single sleeve, on a 10mm fan, can be deep enough to keep fan
    more stable, and if given enough lubricant, can have a good
    service life, but apparently 1/100th of a cent worth of lube is
    even too much to ask... which is why I don't even bother
    anymore, none of my motherboards or video cards have their
    original 'sinks on them except a few Asus, after removing 'sink,
    lapping, and using thermal compound.

    Since your present 'sink does have a removable clip, might it be
    possible to use that clip on a Zalman like this one:
    http://store1.yimg.com/I/svcompucycle_1807_92442713
    (not sure if that link will work, they stripped file extension
    off of it).
    It was from this page:
    http://www.svcompucycle.com/zanoco.html

    You could also look around at electronics surplus 'sites for
    something similar to the following, but with smaller dimensions:
    http://www.allelectronics.com/cgi-bin/category.cgi?category=270&item=HS-70&type=store

    From the poor pictures I saw of your board, the NB clip looks
    pretty thin, perhaps thin enough to slide inbetween the tines of
    many 'sinks not really designed for that type of mounting?

    If you REALLY wanted to use epoxy, it might be better to put
    thermal compound in the middle, something with good longevity
    like a synthetic (arctic silver III, IV, Alumina or Ceramique)
    and attach the perimeter of heatsink base to the northbridge's
    PCB carrier with the epoxy, by using a lot more of it and putting
    a small weight on the 'sink to make sure it bottoms out on the
    northbridge while the epoxy sets, though this procedure could
    require a lot of attention to detail to be sure the contact is
    good, there's no do-overs with epoxy, once it's set you should
    never try to remove the 'sink as it may easily tear half of the
    component off the motherboard instead of releasing at the
    'sink-component epoxy bond... and of course your warranty is
    void, LOL, which seems to be my primary goal most of the time but
    you may have a different objective. ;-)
     
    kony, Sep 1, 2004
    #7
  8. Tony

    Tony Guest

    Wow! You have given me a whole pile of info here! I've been doing this kind
    of thing for quite some time also, but it's always great to get a view from
    an experienced tweaker. Just because I've built and rebuilt a bunch of
    machines doesn't mean my way is always the best way!

    As I was reading through your reply I remembered something that just made me
    smack myself in the head. I have an unused PC Power and Cooling CPU-COOL for
    a 386 sized processor. It's a sink and fan that has a nice thermally
    conductive adhesive on the flat end. I'll bet it will fit pretty good on the
    NB. I think I'm going to give it a try.
     
    Tony, Sep 3, 2004
    #8
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