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. Mark Hull-Richter, Linux Kernel Engineer DATAllegro (www.datallegro.com) 85 Enterprise, Second Floor, Aliso Viejo, CA 92656 949-680-3082 - Office 949-330-7691 - fax -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20070413/fbe88e56/attachment-0004.html>
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?per http://www.amdcompare.com/us-en/desktop/Default.aspx a X2 4200+ -should- be 2.2Ghz, each core. in the MS Windows world, the utils CPU-Z, and SiSoft Sandra, both do a damn good job of groping out all the mainboard and peripheral specifications and benchmark actual speeds, and give it to you as clocks and so forth. I've not seen anything that comprehensive for Linux, other than whats in the various /proc interfaces, and the dmesg stuff at startup.
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.
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. >Well, now, that's just weird! Here's the contents of /proc/cpuinfo on my Dell E521 with the same processor: processor : 0 vendor_id : AuthenticAMD cpu family : 15 model : 75 model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ stepping : 2 cpu MHz : 2205.548 cache size : 512 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 1 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext lm 3dnowext 3dnow pni bogomips : 4412.52 (second core info snipped) You'll note that mine indicates 2205.548 MHz. -- Jay Leafey - Memphis, TN jay.leafey at mindless.com -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/x-pkcs7-signature Size: 4011 bytes Desc: S/MIME Cryptographic Signature URL: <http://lists.centos.org/pipermail/centos/attachments/20070413/bcf96fce/attachment-0004.bin>
Jay Leafey wrote:> 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. >> > > Well, now, that's just weird! Here's the contents of /proc/cpuinfo on > my Dell E521 with the same processor: > > processor : 0 > vendor_id : AuthenticAMD > cpu family : 15 > model : 75 > model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ > stepping : 2 > cpu MHz : 2205.548 > cache size : 512 KB > physical id : 0 > siblings : 2 > core id : 0 > cpu cores : 2 > fdiv_bug : no > hlt_bug : no > f00f_bug : no > coma_bug : no > fpu : yes > fpu_exception : yes > cpuid level : 1 > wp : yes > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge > mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext lm > 3dnowext 3dnow pni > bogomips : 4412.52 > > (second core info snipped) > > You'll note that mine indicates 2205.548 MHz.Don't worry about it, I've had my 1.5Ghz laptop switch up and down, as low as 233 or so. -- Cheers John -- spambait 1aaaaaaa at coco.merseine.nu Z1aaaaaaa at coco.merseine.nu Please do not reply off-list
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?1Ghz means power saving is enabled.