New service photos show unreleased Power Mac G5

In May, Apple distributed at least two revisions of the Power Mac service manuals. The first revision appeared on May 12 and featured only minor alterations, but a successive revision published on the 28th of the month reveals some interesting and previously unseen photos (below) of a dual Power Mac G5.

Larger heatsink cover

Over the last 6 months, AppleInsider has consistently published reports of an all dual processor lineup planned for the next Power Mac G5 revision. In line with these reports, the service manual shows a large and unified heat sink cover. The current models, which can have one or two processors, have one heat sink per CPU.

Sources also speculate that a revised cooling system could be nestled behind the larger plate cover.

Smaller motherboard

Also apparent from the photos is the existence of a much smaller motherboard in the unreleased Power Mac photos; about one third smaller than the board featured in the current Power Macs. A noticeably longer cable is used to connect the board to ports on the face of the unit.

The larger vacant space in the front of the unit could potentially allow for a terabyte of storage, which was rumored as a possible feature of the new Power Macs, via four 250GB hard drives.

Lack of front inlet fans

Sources also note the apparent disappearance of the front inlet fans cooling the CPUs. While the base of the chassis in the new service manual retains a notch for these fans, the upper ceiling of the area has been replaced with a flush metal plate that no longer supports an upper connection notch.

Vertical RAM slots

Currently shipping Power Mac models sport 4 or 8 RAM slots, placed horizontally on the motherboard, while photos of the unreleased Power Mac show 4 visible RAM slots positioned vertically. According to sources, this change in orientation may be due to the absence of the inlet fans. Since air no longer needs to flow through the RAM modules, they can be positioned vertically, freeing up additional space in the chassis.

Summary

It's unclear why these photos have suddenly appeared in Apple service documentation prior to the announcement of Power Mac G5s configured in such a fashion.

Apple sometimes prepares stock photography of products prior to their release. With revisions of the Power Mac G5 previously scheduled to arrive months ago, source said it is likely that these photos could represent an overview of the new 90-nanometer Power Mac G5, now destined for a late June introduction.