Crucial is reportedly readying a successor to its best-selling MX200 performance-segment SSD. The new MX300, which will initially be launched in a 750 GB capacity (model: CT750MX300SSD1), will feature 3D (stacked) NAND flash memory. This particular model serves up sequential transfer speeds of up to 530 MB/s reads, with up to 510 MB/s writes. Looking at the way Crucial is pricing the drive in Japan (JPY ¥24,000), its stateside pre-tax MSRP could very well be sub-$200, working out to a price/GB of at most $0.26. According to the source, the drive could launch later today.