[Beowulf] 1.2 us IB latency?

[Greg Lindahl]

On Mon, Mar 26, 2007 at 06:54:58PM -0400, Mark Hahn wrote:

> or is this an example of message aggregation?

The message aggregation number is said to be run with MVAPICH 0.9.9;
message aggregation is in that version, and can't be disabled.

> also, I'm sorta amazed people keep selling (and presumably buying)
> dual-port IB cards.  doesn't that get quite expensive, switch-wise?

HPC customers don't buy them. Enterprise customers want to know that
they exist, but then they don't buy them, either. Eventually IB will
be like Fibre Channel and enterprise customers will actually buy
dual-port cards.

-- greg