From O'Grady's PowerPage "PowerBook G5 Update: Delays, VRAM and Heat 22 November 2004 07:30 EST Jason D. O'Grady
Readers of this site are already familiar with Apple's Quarterly Promotion (or Q Promo for short) which is a PDF of reduced price Apple product that is available for purchase by Apple employees, friends and family. Usually Apple has products on the Q Promo that are either being discontinued, updated, or in oversupply. Today's Q Promo has all of the PowerBooks on it except the 17-inch model because there aren't that many in the supply chain. This points to a silent update to the PowerBook 17-inch, but a more advanced update to the 12 and 15-inch models.
Along those lines, as mentioned at least three months ago, there are the PowerBook G5 test "mules" roaming the campus, and of course they are in all types of fake enclosures. One of the portables division VP's got fired yesterday, which usually means a project is well behind schedule.
We incorrectly reported that one of the models, an updated PBG4, sported 256MB VRAM chip. It turns out that it was a PowerBook G5, not an updated G4. Both nVidea, and ATI have been experimenting with the video RAM on PowerBook G5 logic boards, but we still don't know the final configuration of the G5 portable video card.
The main problem issue with the PowerBook G5 is heat because Apple also wants to have a machine that can handle multiple video streams at one time. This requires a great deal more VRAM, because the processor overflows (on the one side) and cavitates (on the other side) if there is not enough VRAM to handle the streams of data. nVidia says that they can easily incorporate 256MB VRAM on their chip, but the cooling fan requirements is making the battery drain much faster than originally specified. On Apple's side, they decided that they would also incorporate and extend the active/passive cooling techniques to the VRAM to try and bring that core temp down.
It seems as though 100 degrees Celsius per square centimeter of silicon is the thermal limit for these chips, and inside the enclosure, it is getting close to that thermal limit.
The new Mac OS 10.4 ("Tiger") software which was originally scheduled to be released in September as a "Big Surprise" for the back to school crowd but has had so many headaches with the ASICs, the company said to the software development group, "You have six months to get it right, or we will find someone who can."
Everyone in Cupertino is feeling pressure to succeed and keep the stock price up, and in the mean time, some interim update to the G4 portables will probably come out soon (we thought they would be out by now). From some in the Portable division, they still remark that the G5 will be shown or introduced at Macworld Expo SF in January, but not delivered until late February or March (if all goes well)."
rmkay
