rudholm wrote:
> ceejay Wrote:
>
>>Well, at the top end: a 100Mbps LAN should give you about 50Mbps of
>>usable throughput, so divide 50,000 by 256 to get 195 theoretical
>>streams.
>
> 50Mbps?
>
> I'm curious why you don't expect 100Mb/second from your 100Mb/second
> Ethernet.
Because Ethernet uses Carrier Sense Multiple Access with Collision
Avoidance to control traffic. No Ethernet can deliver its rated
speed, even getting 50% of its rated speed is hard if not impossible if
there is any sharing of the network.
And then you have to add overhead, addressing, error correcting, ack/nak
messages, etc.
For a practical example for Slim users, a WiFi 'b' network is
rated as 11 megabits/second but it rarely can actually
delivery uncompressed audio. This is a problem for SB1 users,
since the SB1 only does WiFi B, and can't do Flac on the fly
The RedBook specifies that stereo music is to be recorded in 16-bit PCM
sampled at 44.1 kHz. A little arithmetic shows that the data stream of
CD audio must be at least:
Data Rate = "X"
= 16 bits * 2 channels * 44.1kHz
= 16 * 2 * 44100
= 1,411,200 bits/second
= 176,400 bytes/second
= 172 Kbytes/second
So while Red Book (or uncompressed audio) is only 1.4 mb/s and that
is only 12% or so of a WiFi "b" link speed, you can't get it.
Assuming that you can get 10% of the rated speed is probably good
engineering.
--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html
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