On Friday 13 April 2007, Mark Hull-Richter wrote: > I know this is a bit OT, but the subject of CPU speed came up here and I > was (and have been for some time) curious: > > What is the actual speed of an AMD CPU? E.g., I have a Athlon 64 X2 > "4200+" but my /proc/cpuinfo shows 1005.164 MHz for the two cores. > > What do those mean? Is there a reference for this (huge) discrepancy? > > Also, is there a way (and what) to tell what the actuall running speed of > memory is? > > Thanks. 4200 is a performance rating... Originally they modeled after a Pentium III, later switched to comparing to Duron performance. With dual core everything got even harder to determine - but important thing is that 4200 is just a relative rating and doesn't mean 4.2Ghz. The 4200+ is a 2.2 Ghz processor. That means it will run at a maximum of 2.2Ghz. Power needed by a CPU is determined by clock speed. So to preserve power, the CPU can clock down. How far and how many steps depends on the specific CPU and board/bios. It seems that your box is fairly idle and the CPU was clocked down to 1Ghz to preserve power. Look in /sys/devices/system/cpu/cpu0/cpufreq. There you will find several files. cpuinfo_cur_freq contains the current CPU frequency and should be the same as you get from /proc/cpuinfo. scaling_available_frequencies are the different frequencies that your kernel/cpu/bios support. You can try it out easily - do something very cpu intensive and then check again, your cpu frequency should have gone up to 2.2Ghz. Peter.