ReadyNAS v2 (RND4000) & WDTV Live Streaming issue

Your read speed is 58 MB/s - 75 MB/s. The files that aren't playing have average bit rates that are < 1 MB/s (e.g. 8000 kbs or less). So the NAS performance is more than 60x faster. Your problem is NOT because the ReadyNAS is too slow - you are on the wrong track.

It is more likely that the ReadyNAS is too fast. In particular, by default the v2 does not enable ethernet flow control (pause frames). Can you see if the the Synology does?

Though I haven't seen this issue with a WD Live, I have seen it with other players (particularly the NTV 550). What happens is that the player itself has a 100 mbit ethernet NIC ("fast ethernet", not gigabit), but asks for more data than can fit on that pipe. The upstream switch ends up overflowing its packet buffer, which kills the streaming throughput. The root cause is really in the player's TCP stack, but from a practical matter 802.3x flow control is an effective work-around.

It is possible to enable flow control on the v2, but it requires ssh. Details are here: https://www.readynas.com/forum/viewtopi ... ol#p389326

Alternatively, If you happen to have a 100 mbit switch lying around you can connect it between the NAS and the ProCurve as a test (or if the ProCurve is managed, try setting the interface speed on the NAS port to 100 mbits). If that solves the problem, then flow control is likely needed. Obviously you wouldn't want to limit your NAS to 100 mbit performance levels - this is just an idea of diagnosing the problem. If this does work, then enabling flow control on the v2 is the next step.