2 x quad-core system is slower that 2 x dual core on FreeBSD

[Krassimir Slavchev]

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Ivan Voras wrote:
> On 20/11/2007, Alexey Popov <lol at chistydom.ru> wrote:
> 
>> CPU states:  5.9% user,  0.0% nice, 81.3% system,  0.0% interrupt, 12.8% idle
>> CPU states: 82.2% user,  0.0% nice, 13.8% system,  0.0% interrupt,  4.0% idle
> 
> Interesting coincidence: 1 CPU generates almost 8x less "sys time" then 8 CPUs.
> 
> But it seems that you have found something real. Inspired by your
> problem I've done a simple measurement ("ab") on a 4-CPU (2x2 core
> Opterons 2216 HE, PAE) machine I maintain, under these circumstances:

Would someone define what exact tests to be performed.
Ok, using "ab" is fine but with what parameters it is used and against
what, script or static html? It will be good to have written some perl,
php ... scripts or C programs which simulates some kind of 'real world'
work.
There are lot of people who thinking 'it is good for me' (including me)
but what can be done with such hardware?

Best Regards

> 
> - a "heavy" PHP application
> - FastCGI
> - in this case, load of 4 clients
> - on 6-STABLE
> 
> and I'm reporting similar findings:
> 
> last pid:  2254;  load averages:  1.43,  0.92,  0.69   up 71+08:23:06  18:00:31
> 153 processes: 8 running, 144 sleeping, 1 zombie
> CPU states: 38.8% user,  0.0% nice, 48.4% system,  3.2% interrupt,  9.6% idle
> Mem: 2321M Active, 1135M Inact, 313M Wired, 139M Cache, 112M Buf, 93M Free
> Swap: 4500M Total, 336K Used, 4500M Free
> 
>   PID USERNAME  THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
>  2208 www         1  99    0   115M 19808K RUN    1   0:06 36.83% php-cgi
>  2207 www         1 100    0   114M 19348K RUN    3   0:05 32.66% php-cgi
>  1715 www         1  99    0   115M 23672K CPU0   0   0:24 27.83% php-cgi
>  1710 www         1 101    0   114M 23460K RUN    1   0:31 22.17% php-cgi
>  1882 www         1  99    0   115M 23392K CPU2   3   0:18 21.34% php-cgi
>  1718 www         1   4    0   114M 22556K sbwait 0   0:21 19.14% php-cgi
>  2677 pgsql       1   4    0   977M 55768K sbwait 0   0:00 28.00% postgres
> 
> We are not so performance bound as you so I didn't do measurements
> earlier. I cannot "play" with settings on this machine as it is in
> production, but ~~50% sys time (the measurement changes around 45% +/-
> 10%) seems too much.
> 
> On another 4-CPU machine (2x2 Xeons 5110, AMD64) with the same
> application and benchmark setup, but RELENG_7, which is not yet in
> production, the results are slightly different:
> 
> last pid: 66564;  load averages:  1.87,  0.48,  0.18   up 15+05:27:03  17:09:09
> 113 processes: 9 running, 104 sleeping
> CPU states: 49.0% user,  0.0% nice, 28.8% system,  0.0% interrupt, 22.1% idle
> Mem: 555M Active, 295M Inact, 884M Wired, 98M Cache, 213M Buf, 135M Free
> Swap: 2047M Total, 2047M Free
> 
>   PID USERNAME   THR PRI NICE   SIZE    RES STATE  C   TIME   WCPU COMMAND
> 66557 www          1 109    0   105M 25340K RUN    3   0:14 64.99% php-cgi
> 66559 www          1 109    0   105M 25308K RUN    2   0:14 62.99% php-cgi
> 66561 www          1  98    0   105M 22196K RUN    0   0:01 12.99% php-cgi
> 66562 www          1  98    0   105M 22196K RUN    1   0:01 11.96% php-cgi
> 59043 nobody       1  47    0  7012K  3744K select 2   0:27  5.96% sqlcached
>   774 pgsql        1  44    0   437M   112M select 2   3:55  0.00% postgres
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