Some Thoughts About MOSFETs . . . .

Add Your Comments

With higher wattage Prescotts showing up, interests turns to the components on the motherboard responsible for feeding the beast, components like MOSFETs.

The problem isn’t with the existence of beefier components able to handle more power and heat, the problem is the cost.

High temperature caps, MOSFETs, etc, all exist; they just belong to higher grade standards than what are currently used.

The standards for parts go as follows (from best to worst):

  • space
  • military
  • industrial
  • commercial

    Space is best; commerical is worst. Space parts cost a lot more; commercial parts are the cheapest. This is understandable given the price of failure in these fields.
    You can’t RMA a motherboard you’ve put on Mars. If you think you’re inconvenienced when a mobo fails, ask someone widowed or orphaned when that happens in a military one. You get the idea.

    This means to me, that if we have to move to more stringent standards and unless some crazy new design methods are being used, we can ALL
    EXPECT TO PAY A LOT MORE FOR OUR MOTHERBOARDS, VIDEO CARDS, etc. as a result.

    High temp parts exist today; it’s just that their cost is prohibitive for
    something like a cookie-cutter motherboard design. VRM modules (the things
    that actually provide your CPU / motherboard power form the power supply)
    are getting significantly more efficient, there are 4 – 6 phase ones now.
    2 -3 phase ones are currently the most used. (The more phases, the less
    frequently a MOSFET has to switch, the less heat it has to dissipate.) However, they cost more.,
    The cost increases because the more phases you have, the more
    MOSFETs you need. Generally, two MOSFETs per phase are used.

    How much more? It depends. Buyers and sellers get together. If Hewlett-Packard-Compaq and Dell start buying millions of high
    temperature parts, the cost of these parts will drop overall (you won’t get the same price as they will, but it won’t be as big a difference
    as it is today.)

    Higher grade components are fine, but there’s a few other effects besides the need to do that.

    For instance, the motherboard and component markets are very competitive. Cost counts, and as the occasional run of inferior capacitors swelling and popping ought to tell you, there’s a big temptation to cut corners. The problem probably won’t be so much with the higher-end, but lower-end mobo/component manufacturers.

    An issue you might not think about is the effect on increased heat on older components. High temperature motherboard components are one thing, but what happens
    when you want to use that ole Sound Blaster 16 PCI from 1998? The parts on
    it are probably ALL commercial grade, 0-85 degrees C. How much heat can IT
    take before malfunctioning? If you stick a furnace inside your box, and you’re using air, you’re going to need to be concerned with the ambient temperature
    of the case.

    If I were Powerleap, or Kingston, I’d be sweating right now and not
    just from my dual Athlon space heater. Powerleap and Kingston make a
    decent living on CPU extender cards / slockets / upgrades. Their products
    are only good on motherboards that have design headroom, ie, if your NEW CPU
    draws 60 amps, your old motherboard better be able to supply it. I don’t
    see how they’re going to be able to sell modern CPU extenders to older
    platforms (like a socket 423 to 478 adapter,) and I’d suspect that they
    would at least attempt it for more modern setups.)

    Given all this, Via / Transmeta / ST / National
    Semiconductor’s efforts at making low power x86 compatible CPUs become even more interesting. As these low-end cpus
    get faster and faster, I think they will start to overtake the average
    Joe market. They will be MUCH, MUCH lower power, smaller size & cheaper.

    And if they’re good enough for the average Joe, why should Joe buy a noisy heater?

    Dave Salquiero

  • Leave a Reply

    Your email address will not be published. Required fields are marked *