The write caching works for me. It's just the progress bar that's always full and the 3xx GB size. The actual caching works though. I am having issues with the built-in speed test though. It'll say it's checking queue and then tell me the place in queue, but it'll stay in that placein queue forever. So even when in place 1 in queue, I'll be there for 5-10 minuten without anything happening.