TCP stack throughput

Timur Irmatov <>
Wed Jul 27 08:51:08 CEST 2005


On 7/27/05, Scott Lystig Fritchie <> wrote:
> Are you using Linux, and if yes, which Linux distribution are you
> using?  I was very surprised to discover that the "top" program
> distributed with Red Hat Advanced Server 3.0, when running on an Intel
> CPU with Hyper-Threading enabled(*), will report that:
> 
> main()
> {
>         int i;
> 
>         for (;;) {
>                 i++;
>         }
> }
> 
> ... will only consume 50% CPU time.
> 
> I don't know why "top"'s behavior is different for AS 3.0: I'm used to
> "top" reporting 100% CPU consumption by a program like that,
> regardless of how many CPUs the machine has.

I had similar experience with squid running on Xeon processor (which
is detected as two processors). As squid is single-threaded app it
uses only one CPU at a time and thus 'top' reports that average usage
of both processors was only 50% maximum..


-- 
Timur Irmatov, JID: 



More information about the erlang-questions mailing list