[time-nuts] PCI-E Serial Card For Windows NTP?
Brian M
brayniac at gmail.com
Fri Jun 26 01:55:02 UTC 2015
Trying not to go offtopic. If there are specific lists for this type of
nuttery, contact me off list - would love to learn and discuss more.
That said - if you're going to test the impact on latency for interrupt
coalescing, I'd suggest using sockperf ping pong test:
https://github.com/mellanox/sockperf
Should reveal a bit more than a simple icmp ping test can. Use the --pps
flag to test a variety of packet rates. Should help show the effect of
coalescing.
- Brian
On Thu, Jun 25, 2015 at 13:40 Hal Murray <hmurray at megapathdsl.net> wrote:
>
> I know next-to-nothing about Windows.
>
> Serial ports are pretty standard. I'd get the cheapest card. I'd probably
> pay a bit more for a second port. It might be handy tomorrow.
>
> One difference between chips is the depth of the FIFO.
>
> PCI card now come in two heights. Make sure you get the right one. The
> short ones don't have room for a second connector. (Some cards come with
> two
> face plates. You can swap in/out the other one if you can use a
> screwdriver.)
>
>
> The other thing to keep an eye on is interrupts from the Gigabit ethernet.
> With a lot of short packets, you can get in trouble spending all your CPU
> time in the interrupt handler. Some hardware is setup to batch interrupts.
> The idea is to delay an interrupt for a while in hopes that more packets
> will
> arrive and get processed as a batch. You may want to turn that off. It's
> a
> tradeoff between latency and CPU usage. You may be able to measure it with
> something like ping.
>
>
>
> --
> These are my opinions. I hate spam.
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
More information about the Time-nuts_lists.febo.com
mailing list