4K TVs are getting cheap as chips these days, and that means you should be getting hold of some 4K video to play on it. There's only one persistent problem with that -- 4K video files are massive, so you need some easy way of storing them en masse and playing them back on your TV conveniently. Enter a multi-bay network-attached storage (NAS) device like this one: Synology's over-sized DS918+ can handle all your house's file storage, PC backups and ultra HD media streaming and more.