Comment Disagree - more valuable now than before (Score 2, Insightful) 423
As CPUs get faster an interrupt costs you more in terms of lost CPU time. So, reducing the number of interrupts is more important now than ever before.
My 100 Mbs ethernet card generates about 5k interrupts / second when transferring data at about 30 Mbps. Gigabit cards are engineered to hold interrupts until a few packets of data come in so that a DMA can move a larger chunks of data. If this NIC reduces the use of interrupts even further (say by off boarding computation or even the entire TCP/IP stack and thus allows for even larger DMA transfers) the impact could be substantial.
Unfortunetly, my knowledge of computer innards stops here, so I can't calculate how much cpu time 5000 interrupts actually take or how the new PCI-Express bus changes interrupt processing or how much a benefit it would be to have say only 1000 interrupts / second instead of the 5000.
My 100 Mbs ethernet card generates about 5k interrupts / second when transferring data at about 30 Mbps. Gigabit cards are engineered to hold interrupts until a few packets of data come in so that a DMA can move a larger chunks of data. If this NIC reduces the use of interrupts even further (say by off boarding computation or even the entire TCP/IP stack and thus allows for even larger DMA transfers) the impact could be substantial.
Unfortunetly, my knowledge of computer innards stops here, so I can't calculate how much cpu time 5000 interrupts actually take or how the new PCI-Express bus changes interrupt processing or how much a benefit it would be to have say only 1000 interrupts / second instead of the 5000.
