At least for the B&W, the fan is variable speed and "thermally controlled and is automatically set to the lowest possible speed to minimize noise". I would assume that remained true for at least some of the G4s, but I have no evidence to support the notion. Every model through the Quicksilver uses the a fan with the same part number, however. Less clear is how the B&W senses the temperature. Is it the fan, itself, the processor, a sensor on the logic board?
When the processor switches to deep sleep mode, it effectively uses no power, so it should give off next to no heat. Now that I've thought more about it, the reason for the huge heatsink on the G4 AGP, and later, must be due to the move of the case-cooler fan all the way to the back. I wonder what the reason behind that was, though. Better cooling for the video card and DIMMs? On Thursday, August 29, 2002, at 05:36 AM, Mark Benson wrote: > On Thursday, August 29, 2002, at 12:42 , Philip Stortz wrote: > >> IIRC, the g4 actually uses and dissipates less power than the g3, >> because it uses finer geometry and hence smaller transistors operating >> with less power per transistor making the total lower even though >> the g4 >> has allot more transistors in it than the g3. > > IIRC the heatsinks on the G4/450 sawtooth were a ridiculous > overkill for normal use, being twice the length of the CPU and 1.5" > high (vague memory...). The reason they are much larger than the G3 > B&W 'sinks is because the fans (one in the back of the case, one in > the PSU) that keep the air circulating turn off completely when the > machine is in deep sleep. This means the G4 CPU has do dissipate > the heat by convection alone. This is the case right up to todays > G4s, the heatsink in a G4/733 is HUUUGGGE, about half the size of > the keyboard and nearly 2" high. I think they fitted small low > velocity fans on the newer G4s to aid sleep-time air-flow a bit or > kept the internal fan on at a guess - don't know for sure. I do > know there have been some sharp rumours that the 1GHz and 1.25GHz > machines get very hot. -- G-List is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- We have Apple Refurbished Monitors in stock! | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> G-List list info: <http://lowendmac.com/lists/g-list.shtml> Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/g-list%40mail.maclaunch.com/> Using a Macintosh? Get free email and more at Applelinks! <http://www.applelinks.com>
