Had an interesting day last Friday setting up machines in an outside broadcast van to record a dozen HD camera feeds of the 6 Nations England Wales rugby match on Saturday. This is for the iview project. This creates a moving 3D computer model from several camera views, which can then be rendered from (almost) any viewpoint to create a (moving) virtual camera view. Sport are very keen to have this, but there's still a lot of work to do.
Anyway, to capture the camera feeds we used 6 rack mount server PCs, each with 6 500GB drives and a dual channel HDTV capture card. It's important to grab uncompressed images, as any compression artefacts would interfere with subsequent processing. The data rates involved are pushing these PCs to the limit, and not everything went smoothly on the day. I'd spent the previous two weeks learning more than I ever wanted to know about Linux's disc caching strategy and memory management, but still didn't get to the bottom of why the process is not 100% reliable.