> On January 21, 2002 19:55, Adam Keys wrote:
> > I'm curious about the performance of the 4-way and 8-way systems. I know
> > nothing about this benchmark. IIRC correctly it simulates chat clients
> > connecting to a server and talking to each other. Is it a CPU, memory, or
> > disk bound benchmark? What is causing the 4-way machines to be only 2x the
> > performance of the 1-way machine and the 8-way machines to be < 3x the
> > performance? Is the system bus the limiting factor on those machines?
>
> Memory bus, lock contention, syncronization issues. SMP really isn't as
> magical as people think after the overhead is taken in to account.
Volcanomark is a Java(TM) chatroom benchmark: multiple rooms, where for each
room, every input from a client generates a write to every other client
(think broadcast storm).
chat (which is a C version of Volcanomark) is useful for testing, as is
hackbench2 (which is cut down to just exhibit the runqueue problem, and
doesn't even use threads).
Hope that helps,
Rusty.
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