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swap G3 for G4 CPU on CPGA360?

Ncc74656

Well-known member
ive read that running a CPU up and around 800 or so mhz on the B&W towers will kick the bus back to 66mhz. due to this im considering a 500 or so mhz cpu upgrade.

the question i have: can i take the zif G3 board and solder any of the CPGA 360 G4 chips to it? or do i need a G4 zif card to start with?

the chips in looking at: 7410 7400 7445? im having a hard time finding data sheets for these old CPU's, not sure if they are all interchangeable.

should just need resistor changes to reduce voltage from G3 to G4, right? then firmware flash on the G3 box itself?

i would love to have a 550 or 600mhz so i was thinking of finding a 500mhz CPU (they are on ebay for 9.00 raw) and jumper over clocking it to 550 or so.
 

Ncc74656

Well-known member
update: i found some specs on these cpu's.
the 7445 has the same # of pins but a different pinout - the L2 cache built in also change voltage requirements. maybe an adapter riser and voltage mod could fix this? but it wont work directly.

the 7410 has a different voltage requirement for the L2 cache as well - 2.5 vs 3.3 so, again, would need a modded riser off the cpga360

it looks as tho the 7400 is the only direct drop. ive found a 550mhz g4 i may order and give it a shot on the G3 board but im not yet sure what changes were made from the physical board between G3/G4
 

Bolle

Well-known member
Check your existing L2 cache chips first. Pretty sure the faster G3 ZIFs use 2.5V or even 1.8V I/O chips so they’ll work just fine with the 7410.
 

Ncc74656

Well-known member
really? thats good to know. im not sure what im doing yet. i dont own any of this hardware. i started wtih a 6360 but even with upgrades - not what i want. so now im looking to mod a G3/G4/quick silver/digital audio into a 630CD case.

there are SO MANY different versions of these computers however. trying to decide on what i want to ebay. the quicksilver is cheaper than the G3's or the Yikes! so im leaning that way
 
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