2.5”: Seagate Constellation (7,200 RPM, 500GB)
The Constellation family, available in 3.5” format at up to 2TB, is now replacing Seagate’s Barracuda ES. However, the Constellation brand also includes 2.5” models, giving Seagate some differentiation while the competition seems set to pick either high density/performance or high capacity.
We looked at the 500GB 2.5” Constellation (ST9500530NS, SATA/300), a cost-effective version for workstation PCs, blade servers, network applications, and high-reliability near-line storage. There’s also a 6 Gb/s SAS version (ST9500430SS). The Constellation drives come with 32MB cache in the 160GB and 500GB SATA models, but cache drops to 16MB if you opt for a SAS/600 interface. The 7,200 RPM spindle speed obviously prevents performance records, but it is the basis for best-in-class efficiency if you look at enterprise-class capacity per watt.
The Constellation ST9500530NS showed the lowest surface temperature in this review, reaching only 47°C (116°F) after 30 minutes of intensive operation. It delivered peak throughput of 95.2 MB/s on our reference test system, which is a bit more than the Savvio 10K.2 can transfer (91.8 MB/s). Seagate’s SAS version is a bit faster at 102 MB/s, and it also delivers slightly better I/O performance. However, have a look at the PCMark Vantage results before making a buying decision. The SATA/300 model is clearly faster than the SAS/600 brother in this benchmark.
The SATA model has another advantage: it only requires 3.0W idle power, marking the lowest power result in this roundup. In contrast, the SAS/600 model required 5.1W. We never measured more than 4.4W for the SATA version, which is a great result for low-power enterprise storage. But there’s always a trade-off somewhere. In exchange for efficiency, you’ll find the Constellations at the bottom of many benchmark charts.
Throughput Diagram
