It's all about picking the most appropriate criteria
Of course the fun thing about performance claims of any type is that it all depends on what your criteria are. The comparisons in this article are primarily focused on performance per rack which actually favors the highest density solutions more than it does the highest performance solutions. I have yet to hear a prospect say “what I really need is xx GB/s per rack” – instead they say “I need a specific amount of usable storage capacity that does at least xx GB/s” and then there’s a multi-vendor race to compete for the business.
At Panasas, for our "world's fastest" claim we have used the metric that we believe has the most relevance to customers: file system performance per disk – how much measurable delivered parallel file system performance across the network to the client is possible per 7.2K SATA drive in the system. For large file throughput workloads accessed by a typical HPC Linux cluster, our customers can reproducibly measure 1600MB/s write throughput from a single 20-drive ActiveStor 12 shelf using the open source IOR benchmark across an optimal network setup, with this result scaling near-linearly with additional shelves. That’s a full 80MB/s per SATA drive in delivered file system performance. To the best of our knowledge, that is still the world’s fastest and allows Panasas to offer more performance for any specific amount of capacity.
I think it's also worth noting that to the best of our knowledge, Xyratex or DDN have never published independent benchmarks proving their file system throughput numbers with the Lustre or GPFS file systems on top of their hardware. Panasas has provided independent third party validation to substantiate its claims (the ESG report that Chris' article referenced).
Ultimately though, what is much more important than performance for most real world deployments is ease of use/manageability along with superior reliability, availability and serviceability – these are all major strengths of Panasas ActiveStor.
Sr. Director of Product Marketing