On Tue, Dec 8, 2009 at 7:10 PM, Hal Murray <[email protected]> wrote: > > [email protected] said: >> Yes but in fact I would like to play with IEEE 1588 as well for work >> reasons! > > Recently (month or two), somebody mentioned that one of the recent Intel > Ethernet chips supports it. > > Another rathole I've avoided, so far.
Yes the next generation of Intel 10 GIGE chipsets do offer timestamp registers for incoming packets. I know a couple of partners building cards around it. However part of the issue is that very FEW companies actually spend the time to design a timestamp framework that makes any sense. I can tell you today I spoke with one vendor who was expecting to piggyback off of Intel's reference IEEE1588 design and believes that is enough. I have found that anything that involves an active network connection to achieve timestamp accuracy is inferior to cards that DO have higher quality crystal oscillators and can HARDWARE LATCH onto a high quality 1PPS (relative to UTC) with zero network transactions (no taking avergae deltas across several transactions over a heavy utilized network). There are some vendors out there that do just that (include a clock as well as the ability to PLL against a 1PPS signal, though what's interesting is that this 1PPS is not standardized across the industry - DOES ANYONE KNOW WHY? It kinda blows my mind.). Of course these cards are an order of magnitude more expensive than your commodity Intel design. -aps _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
