You should mention that ReadyBoost doesn't work like ordinary memory: "Using ReadyBoost-capable flash memory devices for caching allows Windows Vista to service random disk reads with performance that is typically 80-100 times faster than random reads from traditional hard drives. This caching is applied to all disk content, not just the page file or system DLLs. Flash devices are typically slower than the hard drive for sequential I/O, so to maximize performance, ReadyBoost includes logic to recognize large, sequential read requests and then allows these requests to be serviced by the hard drive". Excerpt taken from Wikipedia.