I use centos 6.4 64. I have old proc - CPU AMD Phenom II X4 810 (HDX810W) 2.6 GHz. However, when I execute the command cat /proc/cpuinfo I get the following:processor   : 0vendor_id   : AuthenticAMDcpu family  : 16model       : 4model name  : AMD Phenom(tm) II X4 810 Processorstepping    : 2cpu MHz     : 800.000cache size  : 512 KBphysical id : 0...All four cores have the same speed 800 MHz. How to explain it?
CPU speed and cat /proc/cpuinfo
linux;cpu;proc;cpu frequency
That's the current CPU frequency; it can be scaled up and down.Have a look in /sys/devices/system/cpu/cpu0 (or 1, 2, 3), then the cpufreq directory.Check cat scaling_governor.  It is probably ondemand (I believe that's the default kernel configuration).  Now check scaling_available_frequencies; you'll see a list that for you should start with 2600000.The kernel will boost the frequency when required.  Try a busy loop, with bash:while (( 1 )); do echo busy; doneLet that go and check your frequencies.  They should go up.  If you have a CPU monitor and one of them hits close to 100%, that core will probably be at the max frequency now.