On Thu, 28 Jun 2012, Brian Candler wrote: > As I said: don't use 10GE over CAT6/RJ45 (10Gbase-T). That does indeed have > poor latency. As I understand it: in order to get such high data rates over > copper, it has to employ mechanisms similar to DSL lines, like interleaving, > which means 10G has comparable or even higher latency than 1G. Switches > with all 10Gbase-T ports are expensive, only available from a couple of > vendors, and consume a lot of power. One more thing on the "don't use 10GE over CAT6/RJ45" debate. Where do you get that 10GBase-T has power latency? If you look at 1000Base-T latency ranges from 1us to over 12us with 10GBase-T ranging from just over 2us to 4us a MUCH tighter latency range. When you look ate large packets this is even more pronounced. So yes for very small packets 1000Base-T is faster, but we are talking about 1 - 2 us difference and only on small packets. As far as power, original PHYs were almost 7 Watts per port! Today, almost every switch out there is less then 1 Watt per port and falling based on Moore's Law. ><> Nathan Stratton nathan at robotics.net http://www.robotics.net
