[Andrej]

It would be great for me to know how many watts my computer is using at any given time. I searched on MacUpdate and came up with iStat Menu, but that doesn't seem to display the total wattage. Is there a program elsewhere that can do this?
Searching elsewhere didn't really give me anything relevant.

[ghporter]

Apple publishes their products' normal power usage (in Watts) on this page. For example, my late 2007 (aluminum) iMac uses a maximum of 200W, but approximately 84W while idle with the display on. (The max in is the computer's tech specs, while the other usage is in the Environmental Attributes Listing.) Here you find that this model uses about 1.5W while off and less than 2.0W in sleep, so your extra usage with sleep is not that much at all-less than a lot of "wall roach" adapters.

[reader50]

The specifications usually offer maximum draw, minimum, and (sometimes) typical. If you need more accurate numbers, then you need to do a hardware measurement.

You'll need either an ammeter, or preferably, a wattmeter, to measure the actual draw. Bonus: this can measure your monitor & peripheral loads as well, yielding your total system draw.

[Andrej]

The iMac G5 is not located on that page.

[ghporter]

There are a number of sites discussing this sort of issue with older Macs. The use of the consumer-level "Kill-a-Watt" wattmeter has been documented on several of them. Basically the G5s use less power than the Intel-based iMacs, but specifics are going to be less available because Apple didn't start "environmentally qualifying" Macs until after your machine was removed from production.

[reader50]

Apple has run that page for some years, but is up to their usual tricks - only current models are listed.

The environmental files are still on their server - check the Wayback Machine to see earlier versions of that page, including the download links for earlier machines.

note: The download files themselves probably won't be in the archive, you'll need to extract the Apple download link from the end of the archive download links. In Firefox, use the "cleaned link" function, or extract the apple link manually.