Tech Goes Boom

Where did that little G5 logic board go?

Before the dual 2.5 G5 models were released, rumor sites were abuzz with pictures that had leaked from an Apple service manual. In these pictures, we saw a smaller G5 logic board with vertical RAM slots. It was guessed that this would be the new top of the line logic board and would require 2GB DIMMS to make it to 8GB total of memory. It is more likely that this image was of the new low end model, which only has 4 ram slots. But, when the new G5s emerged, none of them were using this new logic board.

You can see a small image of the new board here at Engadget. This was the only photo I was able to find due to Apple's C&D shock troops. You can also see from these photos that the new 2.5Ghz G5s are not using these new boards. I also checked at my local Apple Store to see if the current dual 1.8 and 2.0s used the new board. They do not.

So what happened here? It looks like Apple was indeed working on a new logic board design for the G5s that would be smaller and have more room to accommodate items like an additional optical drive or more hard drives. It also looks like they were planning on including this new board on it's just released line of G5s, but still using the current enclosure. It is unlikely that these machines were going to include additional drives in the space directly in front of the heatsink though, as this would be passing already warm air over the heatsinks, compromising the cooling of the processors. Instead, it seems like they were going to use the new logic boards in the current case with the current case's limitations. When a new case was ready, the logic board would be ready and waiting for it. Undoubtedly, this decision was rescinded late in the game as it seems service documents were already written to take into account the new logic board. Why it was rescinded is information known only to the people working on the project, but I would suspect that the bean counters were a little late to the table with the cost-benefit analysis. Moving into manufacturing on a whole new board versus just retooling the current boards must have been a financial concern, but it might have been a time concern as well. It very well could be that bugs were found in the hardware at the last moment, and Apple had to retool the current line to accommodate the new products.

It is very possible that Apple will at some point move the whole G5 product line to Liquid cooling, and lessen the need for the current cooling pathways and multiple fan structure within the G5 while still maintaining a quiet, cool design. This would allow the monolithic G5 to include additional drives and perhaps another PCI slot. Or the new board could allow for a smaller, lighter case. Both are desirable outcomes.

Unless there are some large changes, I suspect we will be seeing this board in the future along with a revised case design. But considering the year long wait between the first and second revisions of the G5 line, it may be a long wait.