CO2 Output and Total Cost of Ownership

According to a feature in HPCWire today by Edward J Lucente, the CO₂ output from datacentres is set to increase to about 6% of the US total over the next decade. The data in the article apparently comes from The Uptime Institute.

Although the figures quoted in the article are poor, making comparison between the US and countries such as Netherlands, Malaysia and Argentina; if the data is anywhere near being right then there is something to think seriously about.

I don't mean simply the impact on the globe, I mean the effectiveness of steps that we, the broad IT community, are taking to reduce it.

A substantial part of the rationale for multicore was to keep power consumption and thermal dissipation (understood in this context as being roughly the aircon necessary to keep the datacentre temperature within reasonable bounds) low (on a throughput per watt basis) while power (in the data crunching sense) rose. The target was to keep the growth curve static. Indeed companies such as Intel and AMD regularly show how this was achieved. If the conclusion of the report is true then the design win that we made has not had the effect that was predicted. Since the only way that compute requirements are going is up we must look into why that might be.

Of course, we  don't know the basis of the calculations that The Uptime Institute made, nor more importantly the assumptions that the datacentre managers who were - presumably - interviewed made. However assuming that the conclusion and methodology are valid then the conclusion has to be:

1. that multicore power saving doesn't work as it is supposed to;
2. that data centres / their needs are growing faster than can be compensated for by the decrease in power consumption;
3. that multicores aren't being used efficiently;

Of these (i) seems to be ruled out. It is more likely to be a combination of (ii) and (iii). In fact (ii),(iii) go hand-in-hand. If processing power isn't used efficiently datacentres will grow in order to meet demand. However if it is (see for example piece on Pervasive) then power consumption per item processed drops substantially.

Do we need yet another step change in technology? or should we put a lot more effort into using what we have better. We certainly haven't made best use of MCPs yet and the technology is planned to get much more sophisticated. HOWEVER if the figure quoted are correct then we have to do more as an industry to contribute to reducing CO₂ emissions.