Seagate Constellation ES (ST3200644NS, 2TB)
What’s considered high-end on the desktop is often low-end for business applications. The Constellation is a new business product line based on the same foundation as the Barracuda XT. Therefore, the technical specifications don’t come as a surprise. The Constellation ES is available at up to 2TB with either SAS 6Gb/s or SATA 3Gb/s interfaces.
Capacities of 500GB, 1TB, and 2TB are available with both interfaces, but we found some differences in cache capacity. All SAS drives utilize 16MB of on-drive cache while the SATA models have different buffer sizes. You'll find 32MB in the 500GB and 1TB capacities, while the 2TB is backed up by 64MB cache, very much like the Barracuda XT. However, the latter is specified at a MTBF of 750,000 hours while the Constellation ES specifies 1.2 million hours.
The SATA models are clearly lower on power consumption than the SAS models, probably because of the different controllers, as well as the increased 6Gb/s link speed on SAS. The performance results of the Constellation ES are roughly similar to the Barracuda XT. This product is a great example to show what minor hardware modifications, firmware tweaks, and a different validation can lead to.