Crucial announced worldwide availability of its next-generation solid-state drive late last month. Known simply as the "m4," the company's latest entry is hailed as the successor to its award-winning RealSSD C300, promising to deliver more speed and higher capacities. Despite those claims, we can't help but feel the m4 has some big shoes to fill.The C300 was somewhat of a milestone for the consumer SSD market, being the only flash drive available with SATA 6Gb/s support for quite some time. Whereas most SSD makers opted for the SandForce SF-1200 controller with a peak read rate of 285MB/s, the C300 could hit speeds of 355MB/s courtesy of its Marvell "Van Gogh" 88SS9174 chip. On top of excelling at sequential throughput, the C300 provided strong random performance when working with files of all sizes, making it a well-rounded contender. However, it's been more than a year since the RealSSD C300 landed, and a lot has changed in that time. Above all, the latest SandForce SATA 6Gb/s controllers have been a real game changer.