[Beowulf] Re: typical latencies for gigabit ethernet
d.love at liverpool.ac.uk
Mon Jun 29 17:55:25 EDT 2009
Scott Atchley <atchley at myri.com> writes:
> That is odd. I have only tested with Intel e1000 and our myri10ge
> Ethernet driver. The Intel driver does not let you specify value other
> than certain settings (0, 25, etc.).
I can't remember if I tried it, but it's documented to be adjustable in
the range 100-100000 interrupts/s.
> Your results may be specific to that driver.
Sure. The only ones I have access to which are tunable with ethtool are
the two Broadcoms for which I posted the data.
> I have head that some Ethernet drivers do or will support adaptive
> coalescing which may give better performance than manually tuning and
> without modifying the NIC firmware for OMX.
As I said, not in the case of the ones I tried (even in the low-latency
adaptive mode which the e1000 doc says to use for HPC).
Beowulf mailing list, Beowulf at beowulf.org sponsored by Penguin Computing
To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
More information about the Beowulf