Page 1:SAS Moves On: 6 Gb/s Available Now
Page 2: SAS Features And Basics
Page 3:New SAS 2.0 Features: Expanders, Performance
Page 4:New SAS 2.0 Features: Cabling, Connectors, And Value
Page 5:SAS 6 Gb/s HBAs: LSI First To Market
Page 6:SAS Drives: Seagate Takes The Lead
Page 7: Test Setup And Some Performance Numbers
Page 8: Conclusion
SAS Drives: Seagate Takes The Lead
The product situation is similar on the drive side. We’ve only received a few SAS 6 Gb/s drives from Seagate and one from Hitachi. No one else has provided any SAS 6 Gb/s hardware yet, but we know Fujitsu will follow soon. We’ll mention important performance data for the drives presented on this page, but save the full results for a forthcoming enterprise hard drive roundup.
Hitachi’s Ultrastar C10K300 is a 10,000 RPM, 2.5” enterprise hard drive with a SAS 6 Gb/s interface. It is currently the fastest drive in terms of peak throughput, reaching 341 MB/s with the help of 64MB cache memory. It also does well in our sequential throughput tests, exceeding 140 MB/s. Today, 147GB and 300GB capacities are available.
Since the 2.5” form factor is seeing considerable growth due to higher storage densities, Seagate emphasizes its Savvio 2.5” enterprise drives. The 15,000 RPM Savvio 15K.2 is equipped with a SAS 6 Gb/s interface.
There are 73GB and 147GB capacity points available, both utilizing 16MB cache memory. Read/write seek times from 3.2 to 3.5 ms are very quick. This translates into an amazing 5.0 ms average read access time, and we measured a 307 MB/s interface throughput. Our h2benchw benchmark tracked a maximum sequential throughput performance of 160 MB/s, which is rather impressive for a 2.5” drive.
The Savvio 10K.3 is the 10,000 RPM counterpart in Seagate’s 2.5” lineup. It is similar to Hitachi’s C10K300 in throughput but stays slightly behind at 130 versus 140 MB/s. Look for 300GB and 146GB capacities available now. While Hitachi relies on 64MB buffer memory, Seagate decided to stay with only 16MB. The Savvio 10K.3 isn’t the fastest when it comes to I/O performance, but it is one of the most efficient drives.
The Cheetah 15K.7 is Seagate’s top performance model for the enterprise, delivering an amazing 200 MB/s throughput and access times that are almost at the level of 15,000 RPM, 2.5” drives. Those who want added capacity will appreciate the 3.5” 15K.7’s 300, 450, and 600GB models. Again, these feature only 16MB of cache, but this didn’t seem to hurt the Cheetah 15K.7’s performance capabilities.
Finally, the Cheetah NS.2 10K is a 3.5” 10,000 RPM drive for low-power, high-capacity applications.
There are 600GB and 450GB models available, both featuring 16MB cache and the SATA 6 Gb/s interface. There must be something to the low-power claims, as this is one of the coolest enterprise hard drives we’ve had on our test bench. The 160 MB/s maximum throughput impresses, and I/O performance still behaves well despite this drive’s efficiency ambitions.