First Actual CPU Energy Use Statistics Published

BBCWatcher writes "CNN is reporting that the U.S. Environmental Protection Agency in August asked server manufacturers to develop 'miles per gallon' ratings for their equipment that would provide accurate assessments of energy efficiency. IBM says it is now providing 'typical usage ratings' for its line of z9 mainframe computers, in addition to previously available maximum power ratings. More than 1,000 z9s around the world started reporting (with the owners' permission) on May 11th their actual installed power and cooling demands, so IBM can publish statistics such as how much energy is required to turn on an additional processor to run multiple Linux virtual servers. The answer? About 20 total watts. 'Over time every vendor is going to be asked to provide typical energy use numbers for their equipment. It's what the EPA wants, and this allows us to move beyond simple performance benchmarking to energy benchmarking.'"

The first one though...

[pigiron]

I'm sure it's true that adding additional virtual servers is only 20 watts. But that first one is a real whopper!

Re:damn lies

[Colin Smith]

Oh, but there are so many ways to play with statistics

All the more reason to understand how they work.
 

Performance?

[Speare]

Okay, just stating the wattage is like stating MPG for a car or the energy usage for a fridge. But every year, car performance stays about the same or gets worse, and the fridge ain't getting more full. There doesn't seem to be a single useful energy metric that can drive informed purchasing decisions.

So how do you deal with CPUs that are twice as powerful in the next product cycle? The wattage will be about the same, but the amount you can get done with that chip will be much higher. It's like next year's car suddenly weighs twice as much, or goes twice as fast, or seats two whole families, while getting the same mileage. You can't even consider it in two tiers like "passenger cars vs truck frames" because you have to deal with 2008, 2009, 2010, 2011 performance tiers... they change all the time. How can someone make an informed decision from this?

Re:Tax benefit

[Yartrebo]

Not having a computer is better in terms of energy demand than even having a very efficient computer. Same for the hybrid car. For this reason I find these tax breaks perverse.

Giving tax breaks for efficient items penalizes those who conserve the most by not even having the item or by using less. A business that invests money into writing more efficient software and using less servers should not be penalized vis-a-vis a business that invests the money into more efficient servers.

Re:damn lies

[dgatwood]

While you're at it, account for a more typical load of 10%, account for periods overnight when the machine may be completely idle (for a US-centric web site, for example), etc.

First, everyone has to agree on a series of load metrics which when combined are sufficient to get a good approximation of performance under various types of load (disk-heavy load, CPU-heavy load, etc.). Only then can we really answer the question of how much power a server is going to waste.... :-)

Re:Performance?

[DMUTPeregrine]

Watts per MFLOP. Or MIPS. Or Watts per Point, where point is an average on some benchmarking system. Just giving watts for a computer is like just giving gallons for a car. You don't know how many miles it can go on those gallons, and so the figure is useless.