The world’s third largest disk drive supplier, Toshiba, has upgraded its S300 surveillance disk drive with shingled 4TB and 6TB products, increasing maximum capacity by 50 per cent.
Shingled disk drives take advantage of write tracks being wider than read tracks by having zones of partially overlapping write tracks. This means they can cram more read tracks on a platter, and thereby increase the drive’s capacity. This decreases rewrite performance, as complete zones have to be rewritten at a time. This takes longer than re-writing individual files. But this process can be managed in predictable write load environments such as video surveillance.
Larry Martinez-Palomo, Storage Products Division GM at Toshiba Electronics Europe GmbH, claimed: “The new 4TB and 6TB models improve the total cost of ownership (TCO) for small and medium sized businesses while maintaining performance, quality and reliability.”
He can say that because the two new 3.5-inch drives support 64 high-definition video cameras rather than 32, as they did previously. Their cache buffer has doubled in size to 256MB. The raw performance numbers are the same as before, though: 5.56msec latency and up to 184MB/sec throughput. The new drives spin at 5,400rpm and use a 6Gbit/s SATA interface, again as before.
Toshiba did not release endurance or warranty numbers but we understand they are the same as the prior S300s, meaning a three-year warranty and 600,000 load/unload cycles. The previous 180TB/year workload may increase; the 6TB drive model offers 50 per cent more capacity than the previous 4TB S300.
It did not reveal the number of platters in the drive but assume that, as Toshiba is supporting 2TB/platter elsewhere in its 3.5-inch disk drive range, such as the MG09, then it does so here. On that basis we’d assume 2-platter (4TB) and 3-platter (6TB) models. The only way to reduce the platter count on the 6TB drive would be to increase areal density to 3TB/platter and that tech feat would so advanced as to occasion general amazement in the industry.
