On 2020-05-06 04:04, Stuart Henderson wrote:
On 2020-05-06, Jordan Geoghegan <jor...@geoghegan.ca> wrote:
On 2020-05-04 06:42, Kalle Kadakas wrote:
Greetings OpenBSD community,
I am running into severe bandwidth limitations whilst passing traffic
through an OpenBSD firewall.
The NIC in use is an Intel 10Gb 2-port X520 adapter from which I would
hope to pass through at least 7Gbps+, yet the best results I have
gotten is only around 3.5Gbps.
The results of bandwidth measurements (iperf for 30sec...
As has been discussed on misc previously, iperf is not suitable for
benchmarking networking throughput on OpenBSD. It ends up just
benchmarking the gettimeofday syscall (something that is cheap on Linux,
but relatively expensive on OpenBSD I'm told).
clock_gettime. It's iperf3 that calls this often; iperf not so much.
But when testing with default options, you may see higher numbers from
iperf3: the direct comparison isn't fair though because it uses 128K
TCP buffers by default, whereas iperf uses the OS default.
On Linux clock_gettime often doesn't use a system call, on OpenBSD it
does (and with some of the mitigations for cpu bugs, system calls are
more expensive than they used to be).
For best results, use tcpbench for your OpenBSD networking benchmarks.
For accurate results of packet forwarding performance, use fast packet
sources/sinks running whatever OS either side of an OpenBSD router.
Thanks for clarifying Stuart, I knew I was about 70% of the way there.
Jordan
