True, I have a PC with a 1GB SSD used as ReadyDrive. But it's a separate device that Windows sees as two drives, similar to ReadyBoost except it's built in rather than USB. In non-ReadyBoost aware OSes, you see two drives. As for TiVo - it's all the little I/O that's the issue. Reading big chunks from the disk (i.e. playback) isn't an issue and hard drives are great at that. It's all the little reads and writes that happen. For example, doing database updates after a guide data download can make TiVo visibly more sluggish, or take hours as it reindexes. TiVo does prioritize media accesses over OS and database accesses, so you get stutter free video, but at the expense of possibly sluggish UI as TiVo ensures the media buffers don't underflow which can delay other I/O. Given the nature of the database accesses, the drive might cache the databases and parts of the OS, possibly speeding it up.