Crucial v4 Series in Detail
Whereas the Agility 4 is a reduced version of the Vertex 4, the v4 is an entirely different animal than Crucial's flagship offering. The v4 series consists of four models in sizes of 32GB, 64GB, 128GB, and 256GB. The drives are built in the 2.5-inch form-factor and only support the SATA 3Gb/s interface.
With the v4 series being limited to SATA 3Gb/s, read throughput maxes out at just 230MB/s while write performance peaks at 190MB/s for the 256GB model. The 128GB version is slightly slower at 175MB/s, while the 64GB version sustains just 100MB/s and the 32GB model 60MB/s.
This is the kind of performance that we saw from the Crucial M225 series back in 2009, which has led many to believe that Crucial's parent company Micron Technology is using the v4 series to clear inventory of unused 25nm MLC NAND flash chips.
Whereas the m4 is powered by the Marvell 88SS9174 controller, the v4 carries a Phison PS310. Phison has been around for a long time and they have shipped a huge volume of controllers, though most have been for USB flash drives and memory cards rather than SSDs.
The v4 uses the same NAND flash memory found in the m4 series, Micron 29F256G08CJAAB 25nm MLC NAND chips. And while this memory can achieve great speeds, it will be handicapped by the 3Gb/s Phison controller.
However, the point of this new series is affordability, and the Crucial v4 comes with some of the lowest launch prices ever seen for consumer SSDs. The 32GB model sells for just $50, 64GB for $70, 128GB for $100 ($0.78/GB), and 256GB for $190 ($0.74/GB). The drives are backed by a three-year warranty.