10-10-2009, 12:34 AM
JoeH wrote:
M A V I C, with computers heat output is closely coupled with current draw, about the only thing I know that is more efficient at converting electricity to heat is resistance wire.
It's only closely coupled when the two computers being compared are of similar efficiency. Two G5 processors are capable of pumping out more heat than a dual quad xeon, loaded with RAM, a couple drives and a modern video card. As I mentioned, a Xeon is going to idle about 30° and a G5 around 65° (depending on the model.) That's a difference of about 95°F just in the processors.
That is by far the biggest heat producer out of all of the components.
What were your machines configured with? Well, looking at Apple's site and the document you would have gotten them from, you are comparing fairly minimum configurations, not as I said what they are capable of requiring.
As it is, the configuration of the Mac Pro you site is so minimal to be atypical of any in normal use these days:
Same with the G5. It was minimally configured as well. RAM doesn't really put out much heat, and a drive is going to output as much heat in a Mac Pro as G5. The G5 I cited had 160GB drive, yet you note the Mac Pro has a 320GB.
A baseline comparison between the two is only logical. If you're going to add on a bunch of hardware to the Mac Pro, you need to do the same for the G5. Comparing a loaded Mac Pro to a basic G5 makes no sense.
More RAM, better video card and more drives will all increase the output well past that "max: 1085 BTU/hr" you quoted.
Same is true, if not more true, for a G5. The one I cited was tested with only 512MB of RAM. Upgrade the video card, add more RAM, more drives... in the G5 and it is going to pump out a lot more heat as well.
But, again, it all boils down to the G5 being far less efficient than the Xeon. Even with the Mac Pro having more RAM, larger HD, faster video card... it still puts out almost half the heat as the G5.