(Image credit: Kingston) I remember when an early review sample of the original Intel X25-M SATA SSD landed on my desk. It was the first mainstream consumer SSD and easily the biggest development in PC storage in the last few decades. That was 2008, but it turns out SATA SSDs are still going strong, as in 100 million strong. Kingston has just announced that it has shipped fully 100 million units of its A400 SATA SSD since launching the drive. That's a model that went on sale in 2017, but is still available today . But the key comparison for a SATA SSD like the A400 isn't a cutting-edge M.2 drive. It's one of those antediluvian contraptions with spinning magnetic platters, namely old school hard drives. As several commenters on this Reddit thread discussing the Kingston milestone point out, SATA drives like the A400 are a "life saver" for older PCs. Indeed, I'm not totally convinced most people would immediately know if their fancy M.2 drive was somehow secretly swapped for the likes of an A400.…