power macintosh G5 7,2 from 2003... 970 to 970fx possible?

[svamethyst99]

so i have my old dual 2GHz powermac G5 from 2003 which i've had for about 15 years. and i thought it would be a brilliant idea (sarcasm... lol) to swap the CPUs in it with some spare 2GHz early 2005 processor modules from a parts machine. turns out the system will try to start but it will not chime. if i put normal 970s back in they work fine.

i noticed the 970FX chips take less power compared to the original 970s which i believe took twice as much power, and were a tad faster. i could be wrong but everymac's geekbench scores of the 2003 compared to the 2004/05 models (which may not be accurate, it varies for everyone of course) were slightly higher.

i am curious if anyone has pulled through with such a CPU swap... not sure if an unofficial FW upgrade is possible of course but it would be nice to see the 2003 G5 not take as much power considering these are kinda jank compared to later models. (mine had a friggen factory-applied bodge wire on the mb's underside! if that doesnt say enough idk what will.)

also yes i did try a 7,3 board but unfortunately it was DOA and i don't want to bother getting another one. also are there any advantages with a 7,3 motherboard over a 7,2 other than full support for the 970fx?)

thanks in advance. i know this is one heck of a stupid question but i've been asking stupid questions for my entire life.

 

[alectrona6400]

970fx is not much better in power efficiency, and the 2003 models won't work with that chip. Not a huge dealbreaker considering they're both about the same in performance. A Dual 2GHz PPC 970 setup is already quite nice for me... anything that requires more I just use a different machine. I will say the 2003 does have a bit of an annoying "chirping" issue but it does not adversely affect functionality.