At last months International Supercomputing Conference in Dresden, NASA presented the results of an internal study exploring the suitability of the Cell BE architecture towards accelerating key aspects of climate modeling. Read the full news item
Since they only evaluated a single Cell processor against single core iterations of the competing 'control' processors, those other metrics simply didn't come into play whatsoever in terms of the study results. Wattage and density would obviously be derived by the form the respective solutions took, so shouldn't be difficult to come up with estimates based on shipping solutions.
NASA should evaluate GPGPU from ATI or Nvidia to handle these tasks. In GPGPU task a GPU can justify it's power draw with it's high performance.
Assuming they can even handle the workload... DP performance only achieved parity or surpassed single-socket CPUs this generation, and the flexibility (i.e. range of supported instructions) still isn't on the same level as CPUs.
A couple of things. Firstly your statement above makes it seem as if the Cell doesn't offer a compelling power/performance ratio; it does. Note that upon its launch Roadrunner was not only the fastest supercomputer in the world, but also the most efficient as well. http://www.beyond3d.com/content/news/651 In addition for DP performance, the new HPC Cell revision offers roughly double the DP performance of NVidia's new offerings for much less power draw.... so on a DP Flop/watt basis, it's significant. ATI's Firestream actually itself is the DP leader, but suffers from having a lesser ecosystem surrounding it at the moment. Which is really one of Cell's greatest advantages in the high-end space: it has IBM supporting it, along with IBM's tools. That means something for folk willing to spend hundreds of thousands to millions on an HPC solution. The above is to clarify that "justifying power draw with high performance" isn't something limited to GPUs. That said, as I was browsing around the forums earlier today I stumbled across this thread by Jawed in the GPGPU sub-forum: http://forum.beyond3d.com/showthread.php?t=49266 Uncanny timing, to be sure. I guess porting weather models is the thing to do these days. These test cases were run on a larger scale of hardware than were the tests with Cell, so it's hard to come up with an apples-to-apples comparison (and plus it's a different model), but obviously GPU's do a great job in this realm as well.
That's right. Since it was a NASA evaluation, I was hoping for more thorough reports. Their results seem to focus on speed-up, a line or two on computational efficiency/scalability and a little on porting. I was hoping they do another round of update comparing the latest competitions in more areas such as per-core power efficiency; and the general applicability of Cell vs regular CPUs (or even GPGPU). Higher power also means more expense (due to cummulative power bill, additional cooling and perhaps space). If they are willing to spend more, they could also redirect these "overheads" into more Cell units to bring up the overall performance even further. For easily parallelizable applications, I think GPGPU stands a good chance to proliferate. For others, more work needs to be done.