Elyse Betters Picaro / ZDNET Follow ZDNET: Add us as a preferred source on Google. ZDNET's key takeaways Roku TVs and devices can slow down when cache builds up. A hidden remote shortcut soft resets my Roku and clears cache. Clearing cache is a quick first step, as long as I remember to do it. I have two Roku TVs, one 4K TV with a Roku streaming stick, and a Roku soundbar connected to several Roku speakers. I also have too many Roku streaming devices  lying around in old tech drawers that I desperately need to declutter. Speaking of clearing out junk, it's time to clear the cache on my Roku devices again. Why? When I remember to do it, there's a huge performance improvement. I clearly love Roku devices, but my biggest complaint is that they can get bogged down and start running slowly. Sometimes Netflix takes a few extra seconds to open. Or Disney+ hangs on its logo just long enough for me to wonder whether I should restart my TV.…