On Tue, Jan 19, 2010 at 1:06 AM, Erik Trimble <erik.trim...@sun.com> wrote:
> stupid question here: I understand the advantages of dual-porting a drive > with a FC interface, but for SAS, exactly what are the advantages other than > being able to read and write simultaneously (obviously, only from the > on-drive cache). > And yeah, these Seagates are dual-ported SAS. (according to the spec sheet) > Path redundancy. While it's fairly rare, paths to drives do go down. Redundancy is a good thing :) > Also, a 38% increase in IOPS without LESS drive cache seems unlikely. Or, > at least highly workload-dependent. > Check that, they're claiming 38% better IOPS/watt over the SATA version, > which, given that the SAS one pulls 10% more watts, means in absolute terms > 45% or so. I'm really skeptical that only an interface change can do that. > > Without benchmarking myself, I can't really speak much to their claims. I WILL however say it's VERY unlikely they'd drop the cache on something intended for the enterprise without being extremely confident its performance would be the same or better. It wouldn't surprise me at all to hear the components they use for their SAS interfaces yield significantly better performance. Plus, if it's dual ported... I wouldn't expect to see 38% consistently, but I would expect to see better performance across the board. -- --Tim
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