On Tue, 30 Nov 2010, Jon Dugan wrote: > Excerpts from Usman S. Ansari's message of Sun Nov 28 12:36:44 -0600 2010: > > I am running iperf on two systems connected via 10 GB cards. I am seeing > > lot of > > difference between through put reported by server and client.
> For a TCP test I'd expect them to be pretty close. If those numbers are from > a TCP test I'd like to hear more about your setup. Sometimes they are off a > little bit due to the fact that the interval of time used to calculate the > throughput might vary a bit on client and server. I suggested in private correspondence to increase the duration of the test and this made values converge. So I guess your guess might be right. For short tests could OS buffers also skew results? Or has iperf some kind of acknowledgement protocol to avoid this? > Sometimes the UDP numbers vary a bit because with UDP it's just blasting > packets out without any flow control. In this case the server number is the > accurate number since it will be what it was able to receive. That will at > least be a lower bound. It turns out that UDP reception can be difficult even > for fairly beefy hosts so sometimes the packets are lost a receive time. ------------------------------------------------------------------------------ Increase Visibility of Your 3D Game App & Earn a Chance To Win $500! Tap into the largest installed PC base & get more eyes on your game by optimizing for Intel(R) Graphics Technology. Get started today with the Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs. http://p.sf.net/sfu/intelisp-dev2dev _______________________________________________ Iperf-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/iperf-users
