Re: Socketed 750 CPU's

[gbu@uhc.com (Gary Udstrand)]

>Sorry, I inadvertently added to this confusion by talking about the 750's
>having socketed CPU's.  The 755's have socketed CPU's and come in two
>incarnations: a 50Mhz version and a 75Mhz version.  The 50's are actively
>advertised as upgradable to 75's.
>
>I was told by IBM that they were using a bizarre version of the DX4 which
>came in a 50Mhz version, but this is probably wrong since a clock tripler
>would require a 16.667 Mhz system bus to generate 50Mhz. On the other hand,
>Gary Udstrand seems to think that the 50Mhz version uses a DX2 -- which
>would explain the ability to upgrade: you still have a 25Mhz system bus.
>The only problem with this theory is that the DX2 is a 5 volt chip, the
>DX4's are 3.3 volt chips...

    The 755C 50 Mhz is indeed a DX2 chip (just checked my specs to make
sure), the 75Mhz is a DX4.

>
>To add more confusion to the subject, someone (sorry, I lost the e-mail)
>mentioned that the chip itself is not socketed, but there is a daughterboard
>that is socketed.  Now this would explain a DX4-50, since a daughterboard
>would imply that you have a seprate oscillator as well.

   That would be me, the 755 does have a daughterboard for the CPU.  I have
the upgrade to make my 50Mhz a 75Mhz still in the box (plan to upgrade it
soon  :-)) and it is a daughterboard.



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