Hitachi Ultrastar C10K300 HUC103030CSS600 300GB 10K 2.5" 6Gb/s SAS Hard Drive.

2.5-inch Enterprise Hard Disk Drives

Highlights

• Ultra fast 6Gb/sec SAS for reliable data throughput
  
• Low carbon footprint SAS drive with Advanced Power Management technology
  
• Consumes up to 65% less power than similar 3.5-inch drives
  
• Large 64MB cache buffer manages data efficiently
  
• Occupies 70% less space than its 3.5-inch siblings
  

Applications/Environments

• Space and/or power constrained environments
  
• Enterprise-class servers and networked storage arrays
  
• Blade and 1U/2U rack-mounted servers
  
• Databases and Online Transaction Processing (OLTP)
  
• High performance computing and other 24x7 applications

Performance Spec:

• 64MB Data buffer
• 10,000RPM Rotational speed
• 3.0ms Latency average
• 1669 Mbits/sec Media transfer rate
• 600MB/sec Interface transfer rate (max)
• 143-88 MB/sec Sustained transfer rate (typ.)
• 3.5ms Seek time (read, typical)

See detail spec here.