Re: network speed

[Matthias Scheler <tron%zhadum.org.uk@localhost>]

On 20 Jul 2009, at 17:04, Patrick Welche wrote:
> Indeed - the network seems to be not too bad:
> - dd 1.5GB partition into 3GB RAM tmpfs
> - ttcp -r -s on server
> - ttcp -t < partition on client
> - ttcp with all default tcp values (buflen=8192, nbuf=2048)
>  gives 79215.19, 78265.47, 80459.38 KB/sec so roughly 620 megabit/s ?

Try "ttcp -r -s -b 131072" and "ttcp -t -s -b 131072 <target>", please:

tron@colwyn:~>uname -smr
NetBSD 5.0_STABLE amd64
tron@colwyn:~>ttcp -r -s -b 131072
ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001,  
sockbufsize=131072  tcp
ttcp-r: socket
ttcp-r: rcvbuf
ttcp-r: accept from 81.187.181.118
ttcp-r: 268435456 bytes in 2.47 real seconds = 106232.16 KB/sec +++
ttcp-r: 33980 I/O calls, msec/call = 0.07, calls/sec = 13770.18
ttcp-r: 0.0user 0.2sys 0:02real 8% 0i+0d 0maxrss 0+2pf 3174+11csw
tron@colwyn:~>ttcp -t -b 131072 -s -l 32768 -n 8192 excalibur
ttcp-t: buflen=32768, nbuf=8192, align=16384/0, port=5001,  
sockbufsize=131072  tcp  -> excalibur
ttcp-t: socket
ttcp-t: sndbuf
ttcp-t: connect
ttcp-t: 268435456 bytes in 2.52 real seconds = 104183.62 KB/sec +++
ttcp-t: 8192 I/O calls, msec/call = 0.31, calls/sec = 3255.74
ttcp-t: -1.9user 0.4sys 0:02real 16% 0i+0d 0maxrss 0+8pf 3225+7csw

>   (udp less fortunate at 46773.54, 46820.03, 47666.70 KB/sec so 370  
> megabit/s)


I can get more then that out of my system:

tron@colwyn:~>ttcp -r -s -b 131072 -u
ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001,  
sockbufsize=131072  udp
ttcp-r: socket
ttcp-r: rcvbuf
ttcp-r: 44457344 bytes in 0.38 real seconds = 115586.01 KB/sec +++
ttcp-r: 30204 I/O calls, msec/call = 0.01, calls/sec = 80412.98
ttcp-r: -1.9user 0.0sys 0:00real 10% 0i+0d 0maxrss 0+0pf 472+4csw

But as UDP doesn't have flow control it is hard to tune.

        Kind regards

--
Matthias Scheler                           http://zhadum.org.uk/