Brad Booth

Will New QDR InfiniBand Leap Ahead of 40 Gigabit Ethernet?

David,

Your information about changes being made to the link layer protocols for Ethernet are very correct. The changes will actually be applicable to all IEEE 802 protocols because the work is occurring at the IEEE 802.1 link layer. Ethernet is almost 60% of all the interconnect in the supercomputing network according to market data, and the Ethernet industry is responding with a number of innovations to improve is operation in that market as well as others.

There is some room for questioning the comparison between QDR Infiniband and 40G Ethernet. First, Infiniband specifies their rate as encoded data rate. Unencoded data rate for a 40G IB link is actually 32G. Ethernet only specifies unencoded data rate. Second, the price per port comparison does not appear to be apples-to-apples. Is the IB QDR port an electrical or an optical interface? And where did you get the $500 10GBASE-SR optical module cost as that seems to be a bit dated?

Overall, the link layer comparisons are true, but the physical layer information is a bit off.

Cheers,
Brad