SanDisk ReadyCache SSD FAQ

Hi, I already have SanDisk SSD 128GB drive since one month, but it is not ReadyCache, and I have already installed OS there. But, I didn’t see much speed boost over HDD, maybe I have installed something wrong, or I need to update firmware. Can I try to install ReadyCache software on that SSD? If that could work, I should definitely see the improvements over HDD. It would be nice if OS and data I already installed (about 40 GB) could remain intact. Thanks!