Description of problem: /proc/cpuinfo isn't showing the right values for processor speed. Version-Release number of selected component (if applicable): Various How reproducible: Seems CPU specific, but same on every boot Steps to Reproduce: 1. cat /proc/cpuinfo Actual results: IBM x3755, 2.6.18-128.1.10.el5, AMD 8220 SE: correct results IBM x3650, 2.6.18-128.1.6.el5, Intel 5160 @ 3.00GHz IBM x3650, 2.6.18-92.1.22.el5, Intel 5160 @ 3.00GHz IBM x3650, 2.6.18-92.1.6.el5, Intel 5160 @ 3.00GHz processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R) CPU 5160 @ 3.00GHz stepping : 6 cpu MHz : 1998.000 IBM x3650, 2.6.18-92.1.10.el5, Intel E5430 @ 2.66GHz IBM x3650, 2.6.18-92.1.18.el5, Intel E5430 @ 2.66GHz processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Xeon(R) CPU E5430 @ 2.66GHz stepping : 6 cpu MHz : 1992.000 IBM x3850, 2.6.18-92.1.18.el5, Intel Xeon 2.66GHz (family 15, model 4, stepping 8): correct results Expected results: cpu MHz = actual speed Additional info:
>model name : Intel(R) Xeon(R) CPU E5430 @ 2.66GHz >stepping : 6 >cpu MHz : 1992.000 Brian, Can you do a 'service cpuspeed status' and let me know what it says? P.
It says: Frequency scaling enabled using ondemand governor Ah, when I turn it off then cpuinfo has the right speed reported. I tried loading the machine but it didn't seem to make a difference (I might not have loaded it for enough time, though) The machines which were reporting the right values had cpuspeed turned off. Is there an advantage to having cpuspeed turned on when running a server system?
(In reply to comment #2) > It says: > > Frequency scaling enabled using ondemand governor > > > Ah, when I turn it off then cpuinfo has the right speed reported. I tried > loading the machine but it didn't seem to make a difference (I might not have > loaded it for enough time, though) > > The machines which were reporting the right values had cpuspeed turned off. Is > there an advantage to having cpuspeed turned on when running a server system? Brian, A few things: 1. /proc/cpuinfo "model name" field shows just that -- the actual model name as the processor itself indicates. So, in your case, "Intel(R) Xeon(R) CPU E5430 @ 2.66GHz" is what the CPU is telling the OS the CPU thinks it is. 2. /proc/cpuinfo "cpu Mhz" is the current CPU frequency, or the "real" frequency that the CPU is running at. This number fluctuates depending on the load that is applied to the system. 3. You can find out additional information on cpuspeed by executing a 'man cpuspeed' at a command prompt. 4. There is an advantage to having cpuspeed "on" on a server -- the system conserves power during low loads, as opposed to leaving the CPUs at their highest frequency. Or, as a fellow engineer said, "Check your power bill at the end of the month" ;) P.