Stony Brook Video Server (SBVS) is an Ethernet-based video server from the Experimental Computer Systems Laboratory, SUNY at Stony Brook, and has been fully operational for over a year. The SBVS employs only off-the-shelf PC components and is capable of guaranteeing real-time delivery of digital video streams from the server's disk subsystem, through a shared LAN, to an end user's display. The SBVS integrates a real-time software-based disk array with the Real-Time Ethernet Protocol to provide end-to-end bandwidth guarantee. This article describes in detail how the real-time I/O subsystem interacts with the RETHER subsystem, and the performance cost of this integration. The most recent version of SBVS, a Pentium-90 PC with a six-drive disk array, can support up to 45 simultaneous MPEG-1 (1.5 Mb/s) streams with a single 100 Mb/s Ethernet link, and up to 65 streams with two 100 Mb/s Ethernet links.