[net-perf] Performance test results

[Mike Iglesias]

> One observation is that at 1500-byte MTU, saturation level appears to
> be 941 mb/s of data on a gig link and 94.1 mb/s of data on a fastE
> link. In other words, when iperf is reporting 941 mb/s of data
> throughput (not counting protocol overhead), the router/switch
> interface is reporting 1000 mb/s utilization.  (Strangely, in the
> iperf 2.02, I am also seeing up to 943 mb/s on the same link, so
> perhaps it's doing slightly different math in the later version.)

I've seen ~940mb/s between two systems on the same card/vlan on a
Cisco 6500 router.

I ran a test between UCI and UCLA with the UCI system's mtu set to 8192
(I need to see what the real maximum in Linux is, that worked for now).
I got

UCI -> UCLA   849mb/s
UCLA -> UCI   719mb/s

using "-2m -i 2 -t 10".

What I'm wondering is why changing that would make such a big difference?
So I went and tried it from another system inside campus that still has
it's mtu set to 1500 (we can't change that one due to limitations on the
Cisco card it is plugged into right now).  Here's what I got:

UCI -> UCLA   214mb/s
UCLA -> UCI   630mb/s

Those number are way higher than what I was seeing late last week, so
what has changed between UCI and UCLA?  We're talking about 10x faster
from UCI to UCLA and 2-3x faster from UCLA to UCI.


Mike Iglesias                          Email:       iglesias at draco.acs.uci.edu
University of California, Irvine       phone:       949-824-6926
Network & Academic Computing Services  FAX:         949-824-2069


test systems:  iperf-uci.nac.uci.edu and bwctl-1.border.ucla.net

UCI -> UCLA

RECEIVER START
3327688445.177039: /usr/local/bin/iperf -B 169.232.34.34 -P 1 -s -f b -m -p 5004 -w 2097152 -t 10 -i 2
------------------------------------------------------------
Server listening on TCP port 5004
Binding to local address 169.232.34.34
TCP window size: 4194304 Byte (WARNING: requested 2097152 Byte)
------------------------------------------------------------
[ 14] local 169.232.34.34 port 5004 connected with 128.195.120.5 port 5004
[ 14]  0.0- 2.0 sec  211924900 Bytes  847699600 bits/sec
[ 14]  2.0- 4.0 sec  212030720 Bytes  848122880 bits/sec
[ 14]  4.0- 6.0 sec  210280620 Bytes  841122480 bits/sec
[ 14]  6.0- 8.0 sec  213756400 Bytes  855025600 bits/sec
[ 14]  8.0-10.0 sec  214334340 Bytes  857337360 bits/sec
[ 14]  0.0-10.0 sec  1064869888 Bytes  849811323 bits/sec
[ 14] MSS size 8140 bytes (MTU 8180 bytes, unknown interface)
RECEIVER END


UCLA -> UCI

RECEIVER START
3327688507.491709: /usr/local/bin/iperf -B 128.195.120.5 -P 1 -s -f b -m -p 5002 -w 2097152 -t 10 -i 2
------------------------------------------------------------
Server listening on TCP port 5002
Binding to local address 128.195.120.5
TCP window size: 4194304 Byte (WARNING: requested 2097152 Byte)
------------------------------------------------------------
[ 14] local 128.195.120.5 port 5002 connected with 169.232.34.34 port 5002
[ 14]  0.0- 2.0 sec  185390164 Bytes  741560656 bits/sec
[ 14]  2.0- 4.0 sec  185022200 Bytes  740088800 bits/sec
[ 14]  4.0- 6.0 sec  182360420 Bytes  729441680 bits/sec
[ 14]  6.0- 8.0 sec  172226120 Bytes  688904480 bits/sec
[ 14]  8.0-10.0 sec  174440200 Bytes  697760800 bits/sec
[ 14]  0.0-10.0 sec  902602752 Bytes  719585241 bits/sec
[ 14] MSS size 8140 bytes (MTU 8180 bytes, unknown interface)
RECEIVER END


----------------------------------------------------------------------------
test systems:  iperf-calit2.nac.uci.edu and bwctl-1.border.ucla.net

UCI -> UCLA

RECEIVER START
3327690535.113290: /usr/local/bin/iperf -B 169.232.34.34 -P 1 -s -f b -m -p 5002 -w 2097152 -t 10 -i 2
------------------------------------------------------------
Server listening on TCP port 5002
Binding to local address 169.232.34.34
TCP window size: 4194304 Byte (WARNING: requested 2097152 Byte)
------------------------------------------------------------
[ 14] local 169.232.34.34 port 5002 connected with 128.195.158.11 port 32836
[ 14]  0.0- 2.0 sec  52717248 Bytes  210868992 bits/sec
[ 14]  2.0- 4.0 sec  53792496 Bytes  215169984 bits/sec
[ 14]  4.0- 6.0 sec  53769240 Bytes  215076960 bits/sec
[ 14]  6.0- 8.0 sec  53791128 Bytes  215164512 bits/sec
[ 14]  8.0-10.0 sec  53791128 Bytes  215164512 bits/sec
[ 14]  0.0-10.1 sec  270532608 Bytes  214299549 bits/sec
[ 14] MSS size 1368 bytes (MTU 1408 bytes, unknown interface)
RECEIVER END


UCLA -> UCI

RECEIVER START
3327690483.405262: /usr/local/bin/iperf -B 128.195.158.11 -P 1 -s -f b -m -p 5008 -w 2097152 -t 10 -i 2
------------------------------------------------------------
Server listening on TCP port 5008
Binding to local address 128.195.158.11
TCP window size: 4194304 Byte (WARNING: requested 2097152 Byte)
------------------------------------------------------------
[ 14] local 128.195.158.11 port 5008 connected with 169.232.34.34 port 5008
[ ID] Interval       Transfer     Bandwidth
[ 14]  0.0- 2.0 sec  107480888 Bytes  429923552 bits/sec
[ 14]  2.0- 4.0 sec  173785088 Bytes  695140352 bits/sec
[ 14]  4.0- 6.0 sec  166240696 Bytes  664962784 bits/sec
[ 14]  6.0- 8.0 sec  170231512 Bytes  680926048 bits/sec
[ 14]  8.0-10.0 sec  170154496 Bytes  680617984 bits/sec
[ 14]  0.0-10.0 sec  789815296 Bytes  630442316 bits/sec
[ 14] MSS size 1368 bytes (MTU 1408 bytes, unknown interface)
[ 14] Read lengths occurring in more than 5% of reads:
[ 14]  1368 bytes read 203891 times (72.7%)
[ 14]  8192 bytes read 52393 times (18.7%)
RECEIVER END