My prior post Your Computation Mileage May Vary generated some interesting hallway discussion.
I believe my intended point is valid still which is there is no upper bound in the demand for computational services. My article didn't really make its point too well, which is more about the fact that the computation cost is kind of like rent with utilities included. No incentive to conserve.
But, I need to clarify that it was not my intent to accuse the Internet search companies of being wasteful of resources. Not at all.
One issue is the matter of what Internet searching replaces. For example, Ebay vs. trucking newsprint around in order to occasionally reach my eyeballs with a classified ad or two. Hauling newspaper isn't exactly smart use of resources either.
So by way of setting the record straight on Internet search energy use, colleagues pointed me to some of the facts about this subject. Here are some notes on estimates for energy consumption per search query:
- Standard server-class machines are generally not used. Instead, much more energy-efficient designs are used (careful power distribution, power supply, motherboard design, etc.
- There is a lot of room to do cooling more efficiently than is usually done.
- The "thousands" of computers involved in serving search queries are not all involved for each query. (This part I already knew.)
- Searches take far less than 1 second.
Clearly, if it took anywhere near the energy my blog post suggested to run a search engine, companies like Yahoo, Google, etc. wouldn't be able to make (much) money through search advertising.
Google has previously published some information about energy efficiency, here are a couple:
The above points out that every single PC has an incredibly wasteful power supply in it. Collectively, that's a lot of wasted energy. After reading the above I feel good about buying laptops!
The above says "In the time it takes to do a Google search, your own personal computer will use more energy than Google will use to answer your query."
From my understanding of Internet search technology, and looking at what we can find out publicly about Google, this is entirely credible. Really it is great to know that Google has been successful at lowering the impact of all this great computation capability they're providing.