In a recently posted document titled Improving BGA to PCB Thermo-Mechanical Integrity, IBM describes some of the technologies used to deal with the high heat density of the older 130 nm G5. In the article IBM states that the power output of a 2 GHz G5 970 can "exceed 100 Watts". This number supports our prediction last year that a 1.8 GHz G5 970 would put out approximately 90-100 Watts maximum, which is significantly higher than its 51 Watt "typical" rating. We also know that the 90 nm 2.5 GHz G5 970FX has a similar typical power rating, at 50 Watts, and may also have a similar maximum power output:
2.0 GHz G5 970 typical: ?
1.8 GHz G5 970 typical: 51 Watts
2.5 GHz G5 970FX typical: 50 Watts
2.0 GHz G5 970 max: >100 Watts
1.8 GHz G5 970 max: Probably ~90 Watts
2.5 GHz G5 970FX max: Probably ~90 Watts
However, the 2.5 GHz G5 970FX came out last year, as did those power specifications. As we've mentioned before, we know from Apple's Xserve page that the current 2.3 GHz G5 970FX puts out only 55 Watts max. Clearly there have been significant improvements in the G5 970FX's power utilization. A current 2.5 GHz chip might put out less than 65 Watts, which would likely make a 2.5 GHz dual-core G5 970MP feasible right now. It's also clear that IBM could release higher clocked single-core chips right now too. One can only hope that perhaps IBM's 90 nm process has continued to improve since those 2.3 GHz 970FX power specs were published, enough so that dual-core chips at significantly higher than 2.5 GHz are also feasible.
And of course, we're still waiting to see if IBM can release a mobile G5 with suitable power specs this year as well.