Hacking a motherboard, more than one CPU's



  • I've got an old motherboard (so I'm not afraid to mess it up) and several old CPU's (so I'm not afraid to mess it up) and I had heard somewhere that there is a way to 'hack' a motherboard that can only run one proccessor to run more than one. I find that hard to believe, but if it is possible can someone post some links on how to do it?



  • It is possible, but you have to get your DeLorean up to 88 MPH.  And for God's sake, make sure your flux capacitor is in good working order.



  • I'm going to say almost certainly not possible, for two basic reasons:

    1. Physically, the board can only take one CPU.  It only has one socket, and there are only tracks on the PCB for a single socket.  There's there's physically nowhere to connect a second CPU to.
    2. The chipset (principally the northbridge) will only support a single CPU.  Multiprocessor chipsets are different from (and more expensive than) single processor ones, it would make no sense for a mobo manufacturer to put a multiprocessor chipset onto a single processor board, and a single processor shipset has no way to talk to more than one CPU.


  • Actually one could argue against your second point.  It can be cheaper to have just one manufacturing line pumping out high-end components, and later in the process you can "disable" features and sell it as a low-end component.  I remember not so long ago higher-end CPUs were crippled at the factory and sold as mid-range CPUs.  Turns out you can physically modify it to "unlock" the higher performance.  Here is one example: http://www.atruereview.com/Articles/unlockingkit.php

    This is also true for relatively recent video cards.  In some cases (http://firingsquad.com/hardware/geforce_6800_unlocking/) you can even do it purely in software!

     Of course since this guy's motherboard is "old" I think it's pretty much guaranteed to be impossible to go dual processor.  But if it was a single-core board released in the past couple of months the idea of "hacking" it for dual-core support wouldn't be entirely out of the realm of possiblity; maybe it comes off the same line as its dual-core cousin and is just "crippled" in some way.  Then again it's probably a better idea to just spend a little more money and get a proper dual-core board rather than risk ruining a single-core board; the marginal amount of money you would save these days isn't worth the risk.



  • I once bought a two-processor motherboard with only one processor (Intel Pentium I at the time), with the intention of someday adding a second processor when I could afford it.  So in this case, yes, I could have added a second processor.  (i.e. there exists somewhere a motherboard running with one processor that can accept a second processor, but your motherboard ain't it.)

    By the time I could afford the second processor, that particular revision of the CPU was no longer available and the current revision wouldn't work.  (This was before eBay; I bet I could find it now.)

     



  • [quote user="luke727"]

    Actually one could argue against your second point.  It can be cheaper to have just one manufacturing line pumping out high-end components, and later in the process you can "disable" features and sell it as a low-end component.  I remember not so long ago higher-end CPUs were crippled at the factory and sold as mid-range CPUs.  Turns out you can physically modify it to "unlock" the higher performance.

    [/quote]

    This is not about 'extra speed' or 'more channels' or anything like that. A multiprocessor chipset is fundamentally different and vastly more complicated than a uniprocessor chipset. Nobody will rebadge one as a uniprocessor chipset, because it's just too expensive to waste like that. That would be like taking an Athlon and "crippling" it to be a pocket calculator, for a net loss of pretty much all the value of the chip.

     

    Of course since this guy's motherboard is "old" I think it's pretty much guaranteed to be impossible to go dual processor.

    The oldest multiprocessor PC was a 386 (although it was quite broken - the oldest one sane enough to be able to run a modern operating system is a 486). Age is not the problem.

    But if it was a single-core board released in the past couple of months the idea of "hacking" it for dual-core support wouldn't be entirely out of the realm of possiblity; maybe it comes off the same line as its dual-core cousin and is just "crippled" in some way.

    No. It doesn't work like that. Besides, the board wouldn't have a second socket on it, and it's not like you can build these things out of wire-wrap. They have to be manufactured to micrometre precision (the length, resistance, and capacitance of every connection to a modern CPU is crucial for it to work at all).



  • This is entirely impossible, you have to get a two-socket motherboard. This concept is as sane as my concept of making an elaborate sensor device for a Mindstorms robot out of a defunct digital camera. Even if you had the full specification and wiring diagrams for the processors and the motherboard, which you haven't, and were a wizard with soldering equipment and an expert in PCB design, which you most probably aren't, you couldn't pull it off. Some things simply can't be done on your own... I could say I learned it the hard way ;-)

    There may exist things similar to slotkets that work as CPU multiplexers however. It's at least theoretically possible for two CPUs to emulate one CPU, but I doubt that manufacture of such hardware would be profitable (the trends seems to be the reverse - one CPU emulating two or more, P4 HT for example).


Log in to reply