At the end of July we reported that Western Digital was working on developing two new VelociRaptor hard disk drives with support for the SATA 6Gbps interface and larger caches, and now these HDDs have started to reach retail as they have been spotted in a Japanese store. The two new HDDs to get these additions are the 150GB and 300GB versions of the VelociRaptor HLHX hard drive models, which previously featured only 16MB of cache and support for SATA 3Gbps. Both HDDs introduced recently by Western Digital sport a spindle speed of 10,000RPM, have a latency of 3ms, and an MTBF (mean time between failures) of 1.4 million hours. According to the manufacturer, the updated specs enable the drives to reach sequential transfer speeds of up to 126 MB/s. The drives haven't been priced yet, but with the release of these two new models Western Digital increases the number of VelociRaptor hard drives featuring SATA 6Gbps support and 32MB of cache to four. The other two drives to include these specs have 450GB and 600GB in capacity. In addition, two other VelociRaptor models carry SATA 6Gbps support, while four more come with 32MB of cache. Western Digital's Raptor line of hard disk drives made its debut in 2003 and were the first consumer HDDs to have a spindle speed of 10,000RPM, which enabled them to deliver great performance in most day-to-day applications. This made them a huge hit among enthusiasts, who relied on the Raptor series of drives, often setup in a RAID 0 mode, to power their systems. However, the success of the Rator line was quickly overshadowed by the first generations of solid state drives that provided much better performance without the lag that is characteristic to platter-based storage.