Seagate is a real industry giant in the hard drive market, where you can barely get past if you want to build a high-memory PC system. The range of models covers all segments - from small (2.5 inches) to large (3.5 inches), from green IT (at lower speeds) to high-speed (at 7,200 rpm), from home users to professional environment.This four-terabyte (4 TB = 4,000 GB) volume version of the SkyHawk HDD series is specifically designed for continuous operation, and developers were particularly keen to use video surveillance systems. The hard drive has to do two things: first it has to be extremely reliable, second it has to be fast to record video streams lossless.Both are given at the Seagate SkyHawk. The 3.5-inch HDD is rugged and durable, and is therefore being promoted by Seagate with an enormous MTBF of one million hours. On the other hand, thanks to the 64 MB cache, SATA 6G interface and 7,200 rpm, the HDD is very fast (max. 190 MB / s sustained data throughput), so that even multiple camera streams (up to 64 cameras) can be recorded simultaneously.echnical details:- Dimensions: 101.8 x 26.1 x 147 mm (W x H x D)- Format: 3.5 inches- Weight: about 635 g- Capacity: 4 TB- Speed: 7,200 rpm- Cache: 64 MB- Data transfer rate: max. 190 MB / s- Mean lifetime (MTBF): 1 million hours- Connection: SATA 6G- Power consumption (average / no-load): 5.5 / 3.2 W- Operating temperature: 0 - 70 C