dmesg | grep “MHz processor” | cut -d ” ” -f07 | sed ‘s/[.].*//’

But under Ubuntu Natty 11.04 , this dont work , and only show “evbug”
and the “cat /proc/cpuinfo” its not util for me.

See http://www.redhat.com/archives/nahant-list/2006-January/msg00176.html

what does cpu cores and siblings mean .

@Hristiyan – You might be using an application such as cpufreq. When your CPU is idle it can automatically throttle your CPU down to the lowest speed it can go in order to save energy (electricity costs/etc) as well as extend the life of the CPU. When your CPU gets really busy and 800MHz isn’t enough it should automatically increase it, possibly in increments, or maybe even straight back up to 3GHz. Google a bit for info on your distribution and CPU throttling and you will probably find relevant information on how to check this.

I could always be wrong though. ;)

processor : 0
vendor_id : AuthenticAMD
cpu family : 16
model : 4
model name : AMD Phenom(tm) II X4 940 Processor
stepping : 2
cpu MHz : 800.000

That is just a part of the hole text, but pay attention that: “cpu MHz: 800″. It is not correct, because my CPU speed is 3 GHz. Why is that?
Thanks in advance.

Bear in mind that this long command is more informational than useful as it returns the number of processors – however an application should much rather want to know the number of cores.

VPSs rarely get more than one core. If you have a quad-core physical server shared by 16 VPSs it makes no sense to have more than one virtual core assigned to each VPS.

However if you have a single VPS on a quad-core physical server (there are some scenarios where this is a good idea) then it makes sense to have all 4 cores assigned to the single VPS.

Worker uses multiple threads within a unix process, so is more efficient. Prefork uses multiple processes, so you have extra overhead.

There is no good reason to use prefork at all on any processor, except if you are running Apache modules which aren’t thread-safe. mod_php is the most common one, but you don’t need to use that as there is mod_fcgid and running PHP under fcgi.

One way to find out how many physical socketed CPUs there are is to eliminate any extra cores:
grep core\ id /proc/cpuinfo | grep -c \ 0$
Unfortunately if multiple physical CPUs only have 1 core each this returns zero. The following (clumsy) group of commands will return the number of physical CPUs regardless of if there is only a single core per CPU:
grep core\ id /proc/cpuinfo | grep -c \ 0$ | grep ^0$ >> /dev/null && grep -c processor /proc/cpuinfo || grep core\ id /proc/cpuinfo | grep -c \ 0$

processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 4
model name : Intel(R) Xeon(TM) CPU 2.80GHz
stepping : 1
cpu MHz : 2798.083
cache size : 1024 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 5
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss nx constant_tsc up pebs bts p
ni
bogomips : 5630.31
clflush size : 64
power management:

Any thoughts on how to get the info that I’m looking for?

cat /proc/cpuinfo | grep MHz

2 quads but each of the these physical processors implement hyperthreading

2 x (4×2)=16