Any modern hdd or ssd you find today will be sata 3 and you don't want to be looking at old stuff anyways. Sata is backwards and forwards compatible which means all sata versions will work with each other. You can have a sata 2 device in a sata 3 port or a sata 3 in a sata 1 port, etc. Doesn't matter. It's sata, it works, but the speed will depend on the port. You never mentioned which chronos 7 you have but if it's 2012 or later, it has sata 3 (6gbps). But what version isn't really important. Getting an ssd will improve the speed over a hdd regardless. A samsung 840 evo is a good choice. They aren't too expensive but are one of the best.