Possibly interrupt issues. Where them dmesg'?
On Tue, May 15, 2007 at 07:04:47PM +0200, Renaud Allard wrote:
> Hello,
>
> I just had the opportunity to test some Fluke network equipment, notably
> one which is able to throughput test gigabit networks.
>
> I installed a Nexcom NSA1086 with OpenBSD 4.1-stable and did some tests.
> The NSA1086 units are equipped with a Pentium IV 3.2Ghz (hyperthreading
> disabled), and 1Gb ram. They have 4 sk gigabit interfaces, and 4 msk
> gigabit interfaces. Here are the tests:
>
> **********
> ifconfig sk0 up
> ifconfig sk1 up
> ifconfig bridge0 create
> ifconfig bridge0 up
> brconfig bridge0 add sk0
> brconfig bridge0 add sk1
> sysctl kern.maxclusters=256000
>
> Then I connected the fluke analyzers to both sk ports. connections were
> correctly seen at 1000 base T full Duplex. then I started a throughput
> test on 1Gbps, and I was extremely surprised to see how performance was
> very poor. The throughput was only about 77Mbps.
>
> ***************
>
> Seeing that I decided to try on msk interfaces and got about the same
> "performance".
>
> ***************
>
> Then I configured routing between two interfaces.
> ifconfig sk2 inet 192.168.0.1 255.255.255.0
> ifconfig sk3 inet 192.168.1.1 255.255.255.0
> sysctl net.inet.ip.forwarding=1
> sysctl kern.maxclusters=256000
>
> I did the throughput test, and got about 500Mbps both on sk and msk,
> with the CPU keeping quiet.
>
> **************
>
> So the weak performance doesn't seem related to the bus, the CPU, or the
> sk/msk drivers. Has someone an explanation on why I get this kind of
> behavior?
