E4500 spend one core to saturate 1Gbit/s link with TCP -- is it nornal?

[Eugene Grosbein]

On 21.12.2010 02:44, Lev Serebryakov wrote:
> Hello, Eugene.
> You wrote 20 декабря 2010 г., 22:42:41:
> 
>>>  Is it normal, that 2.2GHz core is needed to saturate 1Gib link with
>>>  only one client (and one TCP connction), or I have something
>>>  misconfigured?
>> Compare with ftpd that uses sendfile() kernel function.
>   simple  "iperf"  shows almost same load (slightly less, but it shows
>   slightly less speed, about 800Mbit).
> 

iperf is bad tool IMHO, it abuses gettimeofday() system call and wastes too much CPU time.
Compare with ftpd that uses sendfile() kernel function.

Eugene Grosbein