At least according to this article at Enterprise Systems. And as interest grows in green supercomputing (at the least for minimizing the disruption of extreme power upgrades, even if you don’t by nature tend to hug trees), HPC center managers need to take energy use from all quarters into account
Much as I hate to contradict the homey wisdom of Kermit the Frog, being green is easier than you think. Tape technology is already helping to keep the data center green as utility bills rise. There is a temptation in the marketplace to label tape as “yesterday’s technology,” but it is hard to make a compelling case to that effect when tape continues to solve today’s problems.
…The efficient use of disk can help with data center greening when a user reads and writes to the densest possible disk array to ensure capacity is maximized and more disk is not bought unnecessarily.
In archiving, on the other hand, the greenest option is tape, which uses less power and produces a lower heat output. This not only eases the bite of the utility bill but places less strain on HVAC systems. In contrast, the case can be made that using disk for archiving does more harm since disks that spin constantly use much more power and generate more heat.
More on this idea in the article, and on the confluence of technology trends pushing tape out and green trends trying to keep it in. The article also talks about MAID (Massive Array of Idle Disks), which I hadn’t heard of.
StorageIO’s Schultz has examined the issue as well, and draws attention to the fact that even MAID does not match the energy cost savings of tape in an off-line environment.