Marc Bevand wrote: > Tim <tim <at> tcsac.net> writes: > >> That's because the faster SATA drives cost just as much money as >> their SAS counterparts for less performance and none of the >> advantages SAS brings such as dual ports. >> > > SAS drives are far from always being the best choice, because absolute IOPS > or > throughput numbers do not matter. What only matters in the end is (TB, > throughput, or IOPS) per (dollar, Watt, or Rack Unit). > > 7500rpm (SATA) drives clearly provide the best TB/$, throughput/$, and > IOPS/$. > You can't argue against that. To paraphrase what was said earlier in this > thread, to get the best IOPS out of $1000, spend your money on 10 7500rpm > (SATA) drives instead of 3 or 4 15000rpm (SAS) drives. Similarly, for the > best > IOPS/RU, 15000rpm drives have the advantage. Etc. > > -marc > Be very careful about that. 73GB SAS drives aren't that expensive, so you can get 6 x 73GB 15k SAS drives for the same amount as 11 x 250GB SATA drives (per Sun list pricing for J4200 drives). SATA doesn't always win the IOPS/$. Remember, a SAS drive can provide more than 2x the number of IOPs a SATA drive can. Likewise, throughput on a 15k drive can be roughly 2x a 7.2k drive, depending on I/O load.
-- Erik Trimble Java System Support Mailstop: usca22-123 Phone: x17195 Santa Clara, CA Timezone: US/Pacific (GMT-0800) _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
