Archives


- Beowulf
- Beowulf Announce
- Scyld-users
- Beowulf on Debian

3x100Mbps: summary

Many of your questions may have already been answered in earlier discussions or in the FAQ. The search results page will indicate current discussions as well as past list serves, articles, and papers.

Search

beowulf at seinfeld.engr.ucf.edu beowulf at seinfeld.engr.ucf.edu
Wed Oct 11 11:50:22 PDT 2000


On Sat, 7 Oct 2000, Laurent Itti wrote:

> Hi all -
> 
> - performance:
>   * check out netperf.org for a test suite and test results.
>   * a single board yields around 94 Mbps throughput
>   * bonded dual-board setups (with another brand for the boards) have
>     been reported to yield around 187 Mbps throughput
>   * with 3 boards we start seeing diminishing returns but still
>     significantly improved performance over 2 boards:
> 
>   setup: Abit SE6(i815), PIII-733EB, 256MB PC133, 30GB UATA/100, 3xRTL8139
>   linux: Mandrake 7.2beta3 (sept 22, 2000), 2.2.17mdk kernel,
>          after experimentation finally it seems that the rtl8139 driver
>          is more stable than the 8139too driver (both included in
>          the distribution; edit /etc/modules.conf to choose; we can
>          still crash the drivers by running the tests below for very
>          long periods...)
>   state: normal boot and runlevel, lots of processes running, i.e.,
>          "real-life" performance test.  Node n11 is running "netserver".
> 
> [root at n01 /root]# netperf -l 60 -H n11
> TCP STREAM TEST to n11
> Recv   Send    Send
> Socket Socket  Message  Elapsed
> Size   Size    Size     Time     Throughput
> bytes  bytes   bytes    secs.    10^6bits/sec
>  
>  65535  65535  65535    60.00     244.06
> 
> 
> [root at n01 /root]# netperf -H n11 -t UDP_STREAM -- -m 10240
> UDP UNIDIRECTIONAL SEND TEST to n11
> Socket  Message  Elapsed      Messages
> Size    Size     Time         Okay Errors   Throughput
> bytes   bytes    secs            #      #   10^6bits/sec
> 
>  65535   10240   9.99        32503      0     266.49
>  65535           9.99        32319            264.98
> 
> 
> we can get up to 280 Mbps UDP send (first line) but then reduce the UDP
> receive (second line), by playing with message size. I'll have to read
> netperf's doc to see what that means ;-)

Unfortunately I don't get very good performance when using 3 bonded
channels.  The results I get for 3 channels is rather dismal.

For UDP_STREAM using ./netperf -H node3 -t UDP_STREAM -- -m 10240

UDP UNIDIRECTIONAL SEND TEST to node3
Socket  Message  Elapsed      Messages
Size    Size     Time         Okay Errors   Throughput
bytes   bytes    secs            #      #   10^6bits/sec

 65535   10240   9.99        34860      0     285.79
 65535           9.99         8635             70.79

I have tryed playing around with the message size but still can't get the
receive numbers anywhere near the send.  Could anyone explain this?


For TCP_STREAM using ./netperf -n 2 -l 30 -H node3 -t TCP_STREAM -- -m
10240

TCP STREAM TEST to node3
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 65535  65535  10240    29.99     138.74

This number is worse then the 2 channel TCP_STREAM test.

------------------------------------------------------------------------

When I use 2 bonded channels using the same commands I get

UDP UNIDIRECTIONAL SEND TEST to bnode0
Socket  Message  Elapsed      Messages
Size    Size     Time         Okay Errors   Throughput
bytes   bytes    secs            #      #   10^6bits/sec

 65535   10240   10.00       23450      0     192.20
 65535           10.00       23443            192.14

TCP STREAM TEST to bnode0
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 65535  65535  10240    29.99     157.57

----------------------------------------------------------------------

And for a single channel

UDP UNIDIRECTIONAL SEND TEST to node0
Socket  Message  Elapsed      Messages
Size    Size     Time         Okay Errors   Throughput
bytes   bytes    secs            #      #   10^6bits/sec

 65535   10240   10.00       11729      0      96.12
 65535           10.00       11729             96.12

TCP STREAM TEST to node0
Recv   Send    Send
Socket Socket  Message  Elapsed
Size   Size    Size     Time     Throughput
bytes  bytes   bytes    secs.    10^6bits/sec

 65535  65535  10240    29.99      94.06

----------------------------------------------------------------------

We have 16 compute nodes and one server/frontend.

Our setup is:
  Motherboard:	SuperMicro P6DGE Intel BX
  Processor(s):	Dual PII-350
  Memory:	256MB PC100
  HardDrive:	FUJITSU 8GB
  Ethernet:	3 x Kingston KNE100TX (tulip)
  OS:		RedHat 6.1
  Kernel:	2.2.17

Does anyone know why the 3 channel network would perform worse then the 2
channel network?  The only real differences between our setups is that we
use SMP nodes, but you have faster processors.  I know that running in SMP
under linux causes the network latency to increase, but could it be the
cause of our 3 channel network problems?

Judd Tracy
jtr at isl.engr.ucf.edu





More information about the Beowulf mailing list