A lot of people tend to forget that the pci-express bus has enough bandwidth on first glance - 2.5gbit/sec for 1gbit of traffix, but apart from data going over it there is significant overhead going on: each packet requires transmit, cleanup and buffer transactions, and there are many irq register clears per second (slow ioread/writes). The transactions double for TCP ack processing, and this all accumulates and starts to introduce latency, higher cpu utilization etc...
Sounds like tools to show PCI* bus utilization would be helpful... rick jones -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
