Monday, December 01, 2008
This one is a neat article, although you would like to work on the figures yourself.
What can we learn from this model? First, we see that power costs not only don’t dominate, but are behind the cost of servers and the aggregated infrastructure costs. Server hardware costs are actually the largest. However, if we look more deeply, we see that the infrastructure is almost completely functionally dependent on power. From Belady and Manos’ article Intense Computing or In Tents Computing, we know that 82% of the overall infrastructure cost is power distribution and cooling. The power distribution costs are functionally related to power, in that you can’t consume power if you can’t get it to the servers. Similarly, the cooling costs are clearly 100% related to the power dissipated in the data center, so cooling costs are also functionally related to power as well.
We define the fully burdened cost of power to be sum of the cost of the power consumed and the cost of both the cooling and power distribution infrastructure. This number is still somewhat less than the cost of servers in this model but, with cheaper servers or more expensive power assumptions, it actually would dominate. And it’s easy to pay more for power although, very large datacenters are often located to pay less (e.g. Microsoft Columbia or Google Dalles facilities).
Since power and infrastructure costs continue to rise while the cost of servers measured in work done per $ continues to fall, it actually is correct to say that the fully burdened cost of power does, or soon will, dominate all other data center costs.