Asus A8N-SLI Premium and watercooling, chipset + pipe = too hot ?

Discussion in 'Asus' started by Jean, Aug 21, 2005.

  1. Jean

    Jean Guest

    Watercooling for the CPU and GPU, but what about the chipset ? Is it safe with only the pipe ??

    it's freaking hot !!!

    i don't think it's possible to install anything else, my video card is ASUS 7800GTX and it's too long.

    Jean, Aug 21, 2005
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  2. Jean

    milleron Guest

    You don't have the motherboard mounted with the heatpipe running
    downward to its heatsink do you? (Some cases like the Lian Li V1100
    and V2100 required the motherboard to be mounted upside down relative
    to conventional cases.) The heatpipe cannot work in that position.

    Several owners have reported chipset temps that they feel are
    alarmingly hot. It's difficult to reconcile that finding with
    situations like mine where I have to touch the chipset for several
    seconds to even tell if it might be warm. I think that when the
    board's mounted properly and the heatpipe is working correctly, the
    chipset will be bordering on "cool." Therefore, if the board's
    mounted in the conventional position, and the chipset is "freaking
    hot," I'd be a suspicious of a manufacturing defect, namely, over- or
    underfilling of the heatpipe with "refrigerant."

    milleron, Aug 21, 2005
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  3. Jean

    Paul Guest

    ASUS 7800GTX and it's too long.
    One thing to point out. The heat pipe on the Premium, moves the
    heat from the Nvidia chip, up to the MOSFET heatsink. To work
    properly, there MUST be air blowing over the MOSFET heatsink.
    That is the heatsink next to the CPU.

    What Asus is expecting, is you have a "normal" fan on the CPU,
    and some air from the CPU fan "spills" onto the fins of
    the MOSFET heatsink. That moving air over the MOSFET
    area should be enough to bring the temperature of the
    heatpipe down considerably.

    Now, consider a couple of other possibilities. You can buy
    aftermarket "tower" style coolers. These blow the air sideways,
    and the CPU cooling air is no longer pointed at the MOSFET
    cooler. Such a tower cooler would be a poor choice for
    the Premium.

    If you use water cooling for the CPU and video card, there will
    be NO moving air over the MOSFET heatsink. Install a fan of
    some sort in the vicinity, to provide that moving air. Set it up
    to blow the air through the fins.

    The heatpipe can only move the heat somewhere. It doesn't
    eliminate the eventual need to transfer the heat to the
    surrounding air.

    Paul, Aug 22, 2005
  4. Jean

    Jean Guest

    thanks... now must a way to install a fan... my case is the Thermaltake Aluminium with no side hole..

    any idea ?
    Jean, Aug 22, 2005
  5. Jean

    Paul Guest

    I have used a couple of techniques to mount fans. I've used an
    aluminum bar with an "L" shaped cross-section. I think it is
    sometimes called "angle iron". I drilled a hole in one end,
    and pushed a PCI slot screw through the hole, and fastened
    the aluminum to a PCI slot. This gives you a piece of
    material to work with.

    Here is a commercial equivalent, only it may not reach far
    enough to place the fan over the MOSFETs. I don't see any
    dimensional drawings on the web page, to allow me to figure
    out how far it reaches.

    I've also used nylon "ty-wraps" to fasten fans to things.
    Find a ty-wrap which is small enough to fit through the holes
    in the fan. If your computer case has a cross-bar, you can
    secure a fan to the cross-bar with the nylon fasteners.
    (These are the same kind of fasteners that are used for
    keeping bundles of cables neat and tidy - you can get them
    at a hardware store or electronics store).

    It can be really difficult to find mounting points for
    unconventional things, inside a computer case. You just
    have to be creative.

    You don't have to draw cooling air from outside the
    case for this cooling application. All you need is to
    get a flow of air over the MOSFET cooling fins.

    Sorry I cannot be of more help, but this is one kind
    of problem where you have to be there in person, to
    find a solution. Virtually any extra screw holes in
    a subassembly in the computer, can be used as an
    anchor point. I don't like drilling holes, unless
    I know in advance it will be necessary, and can
    vacuum out the case after the holes are drilled
    and any metal burrs are removed from around the
    holes. You don't want metal filings floating around
    inside the computer case.

    Paul, Aug 23, 2005
  6. Jean

    Jean Guest

    thanks I did find another solution too...

    But I really wonder if it's necessary...Of course it become vey hot but what are the thermal spec of the
    chipset ? My guess it's made to sustain very high temp.

    Jean, Aug 23, 2005
  7. Jean

    Paul Guest

    Also, before going to all the trouble of finding a means to
    fasten the fan, plug in an 80mm fan to one of the fan
    headers, and just hold the fan over top of the MOSFET
    heatsink. See if the air from the fan, when blowing over
    the MOSFET area, causes the heatpipe to cool off. If, as
    Ron suggests, the heatpipe is defective, it could be that
    the fan won't do anything. My presumption is that the
    heatpipe is working, and just needs some cooling air
    at the destination end.

    To give you an example I've run into. I had a computer with
    a passive heatsink on the Northbridge. I got a digital
    thermometer from the computer store, and it measured 75C on
    the fins of the Northbridge heatsink. That means the silicon
    die underneath the heatsink could be running at 100C. When
    I placed a 40mm fan over top of the heatsink, the fin temperature
    dropped to 37C. That is a pretty good temperature drop for
    such a small fan.

    Paul, Aug 23, 2005
  8. Jean

    Paul Guest

    < hot but what are the thermal spec of the
    That is an excellent find :) Now I won't have to buy any
    more aluminum angle iron, to make my own framing.

    The commercial chip temperature operating range is 0C-70C.
    At 55C, you can only hold a finger on the surface for a
    second or two. At 70C, for a little less time. My own
    personal (not based on science) preference, is to not
    let anything get hot enough to burn myself on. The silicon
    can take the heat, and you will likely replace the motherboard
    before the component reliability is affected.

    Consider conditions inside some of the DTR laptop computers.
    The chips in there are continually roasted, and yet the laptops
    seem to last.

    In a computer, the most important thing to keep cool is the
    disk drive. Its temperature rating is not very high at all.
    Hard drives are affected by both temperature and humidity, so
    if the room air can be kept dry, the temperature is allowed
    to go a lot higher. After the disk drives, any electrolytic
    capacitors are the next thing to keep cool. There are some
    of those next to the processor. There are two big ones, full
    of energy, inside the ATX PSU. Keeping the caps cool, helps them
    to meet their 10 year life expectancy. Even with water
    cooling, there are still reasons to have cooling air moving
    through the computer case.

    Paul, Aug 23, 2005
  9. Jean

    Jean Guest

    thanks.....I let you know what I fianlly did... maybe it will be another waterblock for the chipset ;- )
    Jean, Aug 24, 2005
  10. Jean

    Jean Guest

    I finally find a solution this morning.... It came from nowhere : -)

    reply to I will send you a picture.

    Jean, Aug 27, 2005
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