RE: Iperf Performance
Thanks for the response. I really appreciate it.
Even though I agree on your point that there might be a Network
bottleneck some were down the line, If 2 TCP streams can transfer more
packets and we achieve a much higher throughput
(130Mbytes/sec(2streams)compared to 90Mbytes/sec(1 stream) here)what's
limiting Iperf not to achieve the same when the whole CPU is there for
it to us?
Btw, Netperf was giving us about 130Mbytes/sec for 1 TCP stream but
takes almost 100% CPU.
Is there some tweaking that we could do to increase the throughput of 1
TCP stream to the practical extent the hardware can support?
Thanks for the help,
Samson
-----Original Message-----
From: owner-iperf-users --at-- dast.nlanr.net
[mailto:owner-iperf-users --at-- dast.nlanr.net] On Behalf Of Marc Herbert
Sent: Thursday, August 24, 2006 10:30 AM
To: iperf-users --at-- dast.nlanr.net
Subject: Re: Iperf Performance
On Wed, 23 Aug 2006, Sahadevan, Samson joseph dev wrote:
> When I run Iperf with an I/O buffer size of about 64 bytes (-l 64) and
1
> TCP stream, the CPU remains almost idle (99%-100%) and I get a BW of
> about 90Mbytes/sec (1GB link).
> Is there a way to use the CPU more efficient thereby driving more
> throughput?
The CPU being idle likely means the bottleneck is elsewhere. For
instance you may have a switch or a NIC which has reached its maximum
packet/seconds rate. In this case the CPU can not help.
You can easily verify if the bottleneck (whatever it is) is
packets/second limited by slowly increasing the packet size and
observing the maximum packets/second you get along the way.
Packets/second bottlenecks are typically found in hardware IMHO.
Keep us posted.