Can Apple's Snow Leopard save you money?

Apple's OSX Snow Leopard update offers several noteworthy enhancements, and plenty of behind-the-scenes tweaks--but has anything in the operating system changed in regard to energy efficiency?

We took a 17-inch MacBook Pro and ran it though our standard energy use tests, first under OSX 10.5.6 (a.k.a. Leopard) and then after we installed Snow Leopard, which brought us up to OSX 10.6. Our test system, already Energy Star-compliant, had a 2.66GHz Intel Core 2 Duo CPU, and we had the discrete Nvidia GeForce 9600 graphics turned on.

The differences were minor, but we were able to estimate that running your MacBook with Snow Leopard installed would use about one dollar's worth less electricity than if you kept the older version of OSX.

As our tests are based on a hypothetical usage model, your mileage will vary depending on how much time your system spends off, idle, or doing actual work (and it's worth noting that Snow Leopard includes a newer version of QuickTime, which is used in the part of the testing process). But, when added to CNET's already very positive review of Snow Leopard, it's nice to know that energy efficiency not only didn't take a hit, but also squeaked out a tiny improvement.

So, what are you going to do with that extra 95 cents? You could pick up a single nonpremium MP3 track from your favorite online music retailer, but we're going to track down one more nickel, which will snag us four cans of Coke Zero from the official CNET vending machine.