Topic revisited: 1.42 processor

Question

Hello,
I have a Power Mac G4 Dual 1.25 with 2MB L3 cache per processor(4 MB total). I had to repost this again because for some reason Mac-pro.com lied to me and told me that a 1.42 processor card won't work in the dual 1.25 machine. Although, I now know that the copper heatsink will fit over the 1.25 dual processor card, I also would like to know if the dual 1.42 processor can be used instead of the dual 1.25 in the FW400 logic board? My machine is a 2003(very last before G5) MDD 2003 dual 1.25 w/2MB L3 + dual boots into OS 9.2.2(not that I need it).
I would like a straight, simple answer if I can swap out the dual 1.25 processor and insert the dual 1.42 processor. Oh, and I might as well ask about the copper heatsink again, as mac-pro.com questioned me and told me that neither the heatsink nor processor will work in a dual 1.25 FW400 logic board.
What is known is of course the bus speed is the same: 167MHZ bus, so to anyone out there: WILL ALL OF THIS WORK in a 2003 MDD dual 1.25 FW400?
Because when mac-pro.com once tried it, they told me sob stories that it would not work and what I would get would be a blank screen or if it did work it would not register correctly on system profiler.
Can someone please tell me once and for all that a dual 1.42 + its copper heatsink will work to replace my dual 1.25 processor in a FW400 2003 MDD logic board?
Thank you and Happy holidays!

Answer 1

I see no reason not to swap out a dual 1.25 for a 1.42. Wish I could find one myself to upgrade another MDD I have. I personally didn't have any issues when I installed a dual card, that was taken from a FW800 machine, on to a FW400 motherboard, and the FireWire speed shouldn't be an issue for the CPU in this case. As far as the copper heatsink is concerned, it will fit and is different only in that it is more efficient.
I have heard of several folk who have gotten hold of a copper HS just to run their machine cooler. Just test to make sure the HS is making good even contact with the CPU and use a good quality thermal compound to ensure heat transfer.