Just to be clear, a USB stick is going to be a lot slower than an internal SSD drive, even with USB 3.0 on the external memory device (assuming similar speed memory chips and controller inside each device). An SSD *will* speed up Windows load and application load, as well as any data that you have on that drive and access. It will not noticeably speed up renders in most cases though. The "Readyboost" (that's what it was called, right?) thing was never really that great, and since SSDs are now fairly affordable, it's really not a useful option anymore IMO.
- Oshyan