Hi all, I am currently doing some performance tests with 10Gb NICs and encounter a strange behavior in case when I do Rx and Tx at the same time: while the Rx rate stays more or less stable (almost the same that I see with only Rx traffic) the Tx rate breaks down drastically.
The tests are done with netperf (4 TCP streams for Rx and Tx respectively), the test machine is an Intel i7 (with HT 8 cores at 3,4 GHz) with 16GB RAM running 32 bit FreeBSD 9.0 with default system settings. The results are like the following: TX Only: 2290.32 Mb/s Port=1001 TX 2357.73 Mb/s Port=1002 TX 2340.08 Mb/s Port=1003 TX 2382.87 Mb/s Port=1004 TX TX Total Result: Mb/s 9371 RX Only: 1257.43 Mb/s Port=1001 RX 1901.75 Mb/s Port=1002 RX 2605.19 Mb/s Port=1003 RX 1986.69 Mb/s Port=1004 RX RX Total Result: Mb/s 7751.06 Rx+TX: 251.11 Mb/s Port=1001 TX 3069.74 Mb/s Port=2001 RX 178.35 Mb/s Port=1002 TX 1118.30 Mb/s Port=2002 RX 138.05 Mb/s Port=1003 TX 1661.22 Mb/s Port=2003 RX 129.23 Mb/s Port=1004 TX 1851.75 Mb/s Port=2004 RX RX+TX Total Result: Mb/s 8397.75 While the results for Tx and Rx are similar to what I get on Linux, the results for Tx+Rx are not. On Linux I see total rates of about 15-18 Gb/s. I expected to see the same on FreeBSD and I wonder why I do not. The results are quite the same for Intel, Broadcom and Marvell NICs, so I suspect the cause to be in the protocol stack rather than in the drivers. Is there a known issue concerning high traffic on Tx and Rx paths? Are there any system settings I could adjust to get the expected performance? Any hints are very appreciated. Regards, Lino _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
