thermaltake silent tower in a tower case?

Discussion in 'Asus' started by DS, Sep 7, 2004.

  1. DS

    DS Guest

    Hi

    I'm thinking of the thermaltake silent tower cpu heatsink/fan, but it seems
    a large weight to bolt onto the mobo in a tower case. Has anyone experience
    of this heatsink in a tower pc?

    Thanks
    D
     
    DS, Sep 7, 2004
    #1
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  2. DS

    Paul Guest

    The installation manual is here:
    http://www.thermaltake.com/support/installguide/coolers/cl-p0025SilentTower.pdf

    For additional pictures, I used this review. There are many reviews
    out there, but none I've looked at so far, evaluate Theta-R (thermal
    resistance) for easy comparison to other products:

    http://www.bit-tech.net/review/321/11

    What is good about your A7N8X, is it has four screw holes, so there
    is better support than on an Athlon64, with its two screw holes.

    There is a backing plate, and basically two H shaped pieces of metal
    are bolted to the motherboard. The disturbing part of the design,
    is the copper base of the tower, is only held in place by the cross
    bar of the upper metal "H". I presume the idea, is the crossbar
    functions like a clip - it is a spring and a fastener at the same
    time. I guess, when the upper metal H is clamped down to the board
    with the four top nuts, the crossbar bends and that bend represents
    the spring force and the static load placed on the processor die.

    Base clamped in place by bar
    --- | | --- ___
    |X | | | | X| | | <--- Step in base
    | | v v | | | | (side view)
    | --------- | | |
    | Top view | | |
    | --------- | | |
    | | | | | |
    |X | | X| ----
    --- ---
    -------------------
    | ^^Fan^^ | <-- There is one fan, blowing upward
    ------------------- toward the PSU.


    (Step in base, is on non fan side, and the step goes over top of
    the axis of rotation of the ZIF socket lever arm.)

    Now, when the heatsink is mounted in your case, it will look
    like this, if X-rayed from the end of the tower case looking
    towards the front:
    |
    PSU casing |
    --------------|
    | __________ <---8mm from end of heatsink
    | | | | to upper edge of motherboard,
    | | | | | exhaust baffles against PSU
    | ||+--| |
    | ||| | | Center of mass tries to
    | ||+--| | ---- rotate assembly
    | ||| | | | downward.
    | | | |--------- |
    | | | ^^Fan^^ | v
    | | ----------
    | |<--mobo
    Tray

    When the center of mass pulls down, the only thing to resist it, is
    the clip across the base. The base of the processor and the rubber
    cushions on the CPU will presumably be getting some of this force.
    Other products have their center of mass closer to the motherboard,
    so this is less of an issue. Since the "upper storey" of the
    Silent Tower is alum. fins, I expect most of the mass is where
    it should be, in the base. So, by using my imagination here, I'm
    thinking the CPU is more at risk with this design than the PCB itself.

    The back plate stiffens the PCB, to help prevent local bending. But
    this is only as effective, as the mounting for the PCB itself. When
    the ATX case was designed, no one could have known people would need
    a 1.4 pound weight supported under the CPU, and the position of the
    mounting points near the top of the board, is less than ideal for
    supporting the PCB for a high center of mass heatsink.

    Now, if this assembly receives a shock, you can use the same kind of
    analysis, to understand what the dynamic force onto the processor
    will be. The worst direction for a shock, is a rocking motion of
    the tower, and I wouldn't expect too many G's that way without
    knocking the computer case right over. As the heat pipes would
    bend under a shock, the analysis of what happens would be more
    complicated than for a heatsink fastened directly to the PCB.

    Apparently, on some motherboards, the direction of airflow from
    this product, is towards the back of the computer and the case exhaust
    fans. If I've done my imagining correctly, the A7N8X install will blow
    towards the PSU, and the clearance from the exhaust of the Silent Tower
    is: 8mm + clearance_from_mobo_to_PSU_casing. My guess is based on a
    80mm depth dimension through the fins, halved gives 40mm, and distance
    from center of A7N8X socket to top edge of motherboard is roughly
    48mm. Having the air baffle against the PSU isn't too good.

    I don't know of any data or articles on bending of PCBs, so I cannot
    give a number for what a bad load on a PCB would be. None of the
    reviews of this product expressed any reservations, so I guess they
    didn't see any deflection in the PCB.

    In the review above, of the five heatsinks, I'd select the
    Thermalright based on how it mounts to the board (spring loaded
    screws topside). You can remove it without having to remove the
    motherboard. Have a look on the Thermalright site, for compatibility
    info and AMD heatsink models.

    This review shows several Thermalright models at the top of the
    list:
    http://www.overclockers.com/articles373/socketA.asp

    Silentpcreview also has some nice review articles:
    http://www.silentpcreview.com/article132-page4.html

    I use a Zalman 7000a AlCu on my P4C800-E and it isn't a bad product.
    I can still hear the fan, and run it at full speed. But the mounting
    method varies with socket type, and there is also the clearance issue
    to the PSU on a A7N8X board to consider (about 8mm min from top edge
    of motherboard to PSU casing), so one of the Thermalrights might be
    less of a hassle. For the Thermalright, you'll need a fan
    with a tachometer output, to be able to monitor the fan speed, and
    finding a good one will be the hardest part of your purchase. Panaflo
    fans are nice, but you have to be careful when buying them, because not
    all models have tacho outputs. The ones ending in "BX" part numbers
    might be good ones based on this catalog page. CFMs vary according
    to whether the fan is a low, medium, or a high. The FBA09A12L1BX looks
    like a nice 92x25mm fan, with tacho output. It should be quiet at
    full speed. A FBA09A12H1BX is another option, but would need a
    FanMate voltage reducer to make it run quiet (H is hi speed).

    http://dkc3.digikey.com/PDF/T043/1297.pdf

    HTH,
    Paul
     
    Paul, Sep 8, 2004
    #2
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