The last person that made a simple thread of trying a simple swap of one speed G5 CPU for another -- never got it working right.
And that was with the powermac just doing simple CPU swaps from one speed to another, adding in a new pad to the mix -- ouch.
---
In one of the old posts is the "expert" on G5s and his words of advice on how to accomplish the swap -- and it involved hooking up $10s of thousands of dollars in test equipment, capturing the traffic between it and the EEPROM, and hacking the service processor to find out what needs to be reprogrammed.
aka, cheaper to sell the machine and buy a NEW INTEL box than do it with an older G5.
The G5s are nasty and complex and have driven away some of the smartest tech people from even considering using the thing in their product.
Badandy said:
And this brings up:
Quote:
11.1.2 Power-On Reset SPU Hardware Considerations
It is assumed that 970FX systems will include a service processor (SPU) which generally consists of a low cost microcontroller. This microcontroller is responsible for hardware initialization of the 970FX and the North Bridge and can also be used to manage and supervise other system functions, like fans. At a minimum, the SPU needs to be able to assert HRESET_B and BYPASS_B on the 970FX and should also have either a dedicated I2C bus master to initialize the system, or general purpose I/O pins (GPIO) that can be used to implement an I2C bus master.
Anybody thinking of "hacking" or "overclocking" this system should be sobered by the complexity of what is required to bring the system up and configure it out of reset. We will be waiting for the "Refer to the IBM PowerPC 970FX Power-On Reset Application Note for details." ... and the details look very detailed.
Information from Momentum makes it clear that intializing the bus includes loading pin-pin bus skew parameters (which are PCB design dependent and frequency dependent). These are stated to take roughly a week of detailed testing for each new PCB design to establish (sheesh!).
Edit: keep the same speed and add the 2nd socket, get the Apple service DVD to calibrate the CPU, and find another dual socket machine to see if the resistor pads and jumper pads are changed (and if they are copy that down -- and possible copy the service processor EEPROM, and/or possibly the machines boot EEPROM).
