The Crucial M4 was a solid-state drive in the 2.5" form factor, launched on April 26th, 2011, that is no longer in production. It was available in capacities ranging from 64 GB to 512 GB. This page reports specifications for the 128 GB variant. With the rest of the system, the Crucial M4 interfaces using a SATA 6 Gbps connection. The SSD controller is the 88SS9174 Van Gogh from Marvell, a DRAM cache chip is available. Crucial has installed MLC NAND flash on the M4, the flash chips are made by Micron. To improve write speeds, a cache is used, so bursts of incoming writes are handled more quickly. The M4 is rated for sequential read speeds of up to 500 MB/s and 175 MB/s write; random IO reaches 45K IOPS for read and 35K for writes.
The SSD's price at launch is unknown. The warranty length is set to three years, which is above average, but shorter than the five years offered by many other vendors. Crucial guarantees an endurance rating of 72 TBW, a good value.