Iperf CPU usage at 100%
 

Hi,

I use Iperf for network benchmark, both tcp and udp, but while running udp tests the CPU gets 100% usage. My OS is centos 5.3 x64 and the iperf is 2.0.4-1.el5. The CPU are 2x Intel(R) Xeon(TM) CPU 3.20GHz in a HP Proliant G3.

Can you help me?

Thanks

Sounds like a pretty intense benchmark test ;-)

I'd be curious to compare the results on a different machine. Specifically:

1. Does CPU go to 100% on the other platform?
<= Remember "High utilization" is *not* necessarily a bad thing: it might just mean you're doing a lot of work!

2. Is the UDP throughput as high (or higher)? Or a lot lower?

Just curious .. PSM

1. If i do the same test with a Windows machine, the cpu usage is normal.
2. The highest throughput that i use is 8Mbps. Sometimes i also test with 4Mbps, 2Mbps and 400Kbps.
I think is bug...

Does anyone has the same problem?

Yep, when I leave iperf running in daemon mode, it hogs up all the CPU (even with no active clients).

Scenario, I run 'iperf -s -D' on an internal server, go to other machines, test a few times, then forget about it. Later, the server machine is locked up at a load of 6.00 and iperf is at 100% CPU. The test server has nothing else active on it...

iperf version 2.0.5
platforms: FreeBSD 8.4 and 9.1

If i run 'truss' on the PID, nothing is returned, yet iperf is still churing away at 100% CPU. How is this possible? :)