Can the Synology DiskStation stream Hi-def videos?
Yes, the Synology DiskStation can stream Hi-def files, if you look at a Blu-Ray DVD stream, the bandwidth required is typically not greater than 30Mbps. So, even a DS-106e running with a wired 100Mbps can stream 1 Hi-Def signal to a Hi-Def DMA.
That being said, all current Synology DiskStations can support up at the very least, 1 Hi-Def video signal.
How many simultaneous streams can the DiskStation perform at once?
Note: these estimates are based on performance data within our lab - actual performance may vary depending on network environment.
DS1010+ --> about 15
DS409+ --> About 6
DS409 --> About 3
Can the Synology DiskStation stream Hi-Def video over Wi-fi?
This is not a question of the DiskStation, it is a question of your network to see if it can handle a Hi-Def streaming. I personal don't recommend using Wi-fi because of the low bandwidth available (if it's specified for 54Mbps, you're likely getting 20Mbps, in my experience) or the high-latency of wireless. (Latency in wireless can easily approach 50-100ms, while a wired connection is less than 1ms)