Hi, I'm using here a Gigabit Ethernet network and some UN*X machines, among others some Linux-based (Kernel 3.x) and one running FreeBSD 9.1-RC1. Using iperf (in TCP mode), the IPv6 bandwith between two Linux machines (directly attached to the same switch) is about 925 Mbit/s, IPv4 bandwith is about 935 Mbit/s. But now it gets exciting: The IPv6 bandwith between a Linux machine and the FreeBSD machine is around 450 Mbit/s (each direction). But the IPv4 bandwith between the same machines is 700 (Linux -> FreeBSD) to 920 (FreeBSD -> Linux) Mbit/s. Little table (values in Mbit/s): Configuration v6 v4 ======================================Linux -> Linux 925 935 # <= This could be v6's 40B header # vs. v4's 20B Linux -> FreeBSD 450 700 FreeBSD -> Linux 455 920 ====================================== The FreeBSD->Linux value shows that the ethernet chip on the FreeBSD machine (it's Intel stuff on both sides, using the em(4) driver on FreeBSD) is able to send at full 1G speed. But why is IPv6 so slow? Regards, Norbert
I'd guess it has to do with incomplete offload code for ipv6, but I'm sure you'll see bz chiming in with details. :-)
On 28/08/2012 17:38, Norbert Aschendorff wrote:> Configuration v6 v4 > ======================================> Linux -> Linux 925 935 # <= This could be v6's 40B header > # vs. v4's 20B > Linux -> FreeBSD 450 700 > FreeBSD -> Linux 455 920 > ======================================> > The FreeBSD->Linux value shows that the ethernet chip on the FreeBSD > machine (it's Intel stuff on both sides, using the em(4) driver on > FreeBSD) is able to send at full 1G speed. But why is IPv6 so slow?There are some more numbers, FreeBSD-FreeBSD here: http://people.freebsd.org/~bz/bench/ Apparently, the software stack is capable enough so it may be a driver problem in your case. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 260 bytes Desc: OpenPGP digital signature Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20120829/c1d16cf5/signature.pgp
Norbert Aschendorff <norbert.aschendorff <at> yahoo.de> writes:> ... > Little table (values in Mbit/s): > > Configuration v6 v4 > ======================================> Linux -> Linux 925 935 # <= This could be v6's 40B header > # vs. v4's 20B > Linux -> FreeBSD 450 700 > FreeBSD -> Linux 455 920 > ======================================> > The FreeBSD->Linux value shows that the ethernet chip on the FreeBSD > machine (it's Intel stuff on both sides, using the em(4) driver on > FreeBSD) is able to send at full 1G speed. But why is IPv6 so slow?Norbert, may I ask you to provide one more stats item for this table, if you can ? FreeBSD -> FreeBSD ??? ??? Thanks, jb
So, I got the results using the Live system.
Machine [1] is an older Thinkpad T61 (running the Live system), Machine
[2] the well-known "FreeBSD" machine from the previous benchmark. Both
machines run FreeBSD 9.1-RC1 GENERIC.
{Values in MBit/s}
Configuration IPv6 IPv4
---------------------------------------
[1] -> [2] 450 600
[2] -> [1] 401 855
This confirms the FreeBSD IPv6 receive rate measured with Linux as
sender (iperf client).
Norbert
Norbert Aschendorff <norbert.aschendorff <at> yahoo.de> writes:> ... > {Values in MBit/s} > > Configuration IPv6 IPv4 > --------------------------------------- > [1] -> [2] 450 600 > [2] -> [1] 401 855 > ...Well done. Thanks. jb