[mythtv] Thoughts on encoder farms / distributed capturing and viewing

[James da Silva]

Hi Robert, 

 > I just tried this at home I xfer 3 7??M files from a Redhat 7.3 Box to a 
 > Redhat 8.0 Box and my Xfer rates were 5mb accroding to the FTP Client.  
 > NFS might be faster then FTP but still the max I am getting is 5mb over 
 > my cheapo switch and intel / reltek 8139 cards.

1. Your FTP is almost certainly disk-bound, not net-bound.
2. FTP usually reports results in megabytes, not megabits, so check this.
3. Unless something is really old or broken in your network, you should be
   able to expect to achieve close to full network rates for the proposed
   application (multiple clients sending to/from a file server) from the
   network cards/stacks.

So if we take 4 mega_bits_ per second for the compressed video stream, we
could have a home PVR network with, say, 2 recorders and 4 viewers running
simultaneously for a total of 24 megabits using only 25% of our network.
The average IDE drives will be the bottleneck long before the network.

In '97 using PPro 200s and run of the mill 100TX cards/hubs I wrote an app
that just dumped video/audio directly from the grabber to the net using
multicast udp, and on the other end reassembled frames and dumped them to
the screen/sound card.  At 320x240 this took ~40mbps.  The hardware had no
trouble whatsoever handling this.  Today's systems won't even blink.

Jaime