Archived from groups: alt.comp.periphs.mainboard.abit,alt.comp.hardware.homebuilt (
More info?)
"kony" <spam@spam.com> wrote in message
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b9aj0d2flocb580ch1dascajq1de6k260@4ax.com...
> On Tue, 31 Aug 2004 19:44:43 -0400, "Tony" <none@none.com> wrote:
>
>
> >> 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.
> >>
> >> >
> >
> >Which passive sinks have you used on the NB?
>
> 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
>
>
> >
> >> >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.
> >> >
> >>
> >>
> >> 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.
> >
> >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.
>
> 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. ;-)
>
>
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.
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