🚀 go-pugleaf

In comp.os.msdos.misc (subj: Run 33MHz CPU at 40/50MHz?), francis@ac.dal.ca writes:
> I have a 486DX/33MHz system, and I have been told by the manufacturer that
> the motherboard is upgradeable to 50MHz by plugging in a new crystal and CPU.
> 
> Question:    Is it possible to plug in (say) a 40MHz or even a 50MHz crystal
>     into the board *without* replacing the old (33MHz) CPU? 
> If so, is there a performance improvement or will the 486DX 33MHz chip just
> burn itself out, ie, has it been internally hardwired for the specified clock
> frequency of 33MHz?  I would like to hear from anyone who has attempted this
> (with/without success).

Most likely results:
      Flakey processor.  A 33MHz-rated chip is designed to run at 33MHz
      under worst-case conditions.  So, if you run it faster:
         - it may or may not work, even under 'optimum' conditions
         - it almost certainly will not work as the chip heats up.
      Luckily, I believe the innards of the chip are CMOS, so if the chip
      overheats it won't start thermal run-away and "catch fire".  However
      running the chip too hot will probably destroy it over time as 
      metal migration and other nastys occur.

   Suggestion: Don't do this.  Even if it seems to work for a while, you
   may be corrupting memory and your disk!

                        - Bruce Erickson
                        Hewlett Packard
                        bae@col.hp.com