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
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.
Peter Arremann wrote:
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.
Pentium IV, not III I thought. No point comparing with Duron, it's one of AMD's own processors. When Intel redid its implementation, AMD kept on extrapolating from the older Pentium IVs so as to continue using the same measuring stick (and getting bigger numbers might be nice too).
On Friday 13 April 2007, John Summerfield wrote:
Peter Arremann wrote:
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.
Pentium IV, not III I thought. No point comparing with Duron, it's one of AMD's own processors. When Intel redid its implementation, AMD kept on extrapolating from the older Pentium IVs so as to continue using the same measuring stick (and getting bigger numbers might be nice too).
Glad that thread is already marked as off topic :-) AMD first used PR numbers for the K5 comparing it with the P54C Pentiums... They then re-based for the K6. And the K7. And then for the Athlon64s... The Athlon XP was unofficially compared to the P4 numbers... And somewhere in the middle they compared XP performance against their earlier Thunderbird Athlon models as well. And then AMD wondered why their quantispeed nonsense never really became popular with consumers :) All that is up on wikipedia and many other sites...
Anyway, this is what I remember cause a friend of mine was working at intel in europe at that time. AMD ran into issues in some European countries where competitive commercials are not allowed. That means you can't advertise your product as being 20% faster as something from another company. Although I can't remember AMD ever saying they compared to the Pentium 4 - they for a while had the statement saying that their performance index was a relative speed measure comparing to a Duron... I found a few emails in german pointing to that but nothing official...
Peter.
On Sat, 2007-04-14 at 07:46 +0800, John Summerfield wrote:
Peter Arremann wrote:
<SNIP>
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.
Pentium IV, not III I thought. No point comparing with Duron, it's one of AMD's own processors. When Intel redid its implementation, AMD kept on extrapolating from the older Pentium IVs so as to continue using the same measuring stick (and getting bigger numbers might be nice too).
For the X2 series the number is much simpler. it's just the CPU clock rate times two, subtracting 200 if the CPU has 512K cache per core.
Paul
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.
On 4/13/07, Jay Leafey jay.leafey@mindless.com wrote:
Mark Hull-Richter wrote: Well, now, that's just weird! Here's the contents of /proc/cpuinfo on my Dell E521 with the same processor:
<snip>
cpu MHz : 2205.548
<snip>
You'll note that mine indicates 2205.548 MHz.
As someone earlier pointed out, that could be because mine was relatively idle when I took the snapshot. I'll check it out later when it's busy and see what turns up.
mhr
Mark Hull-Richter wrote:
As someone earlier pointed out, that could be because mine was relatively idle when I took the snapshot. I'll check it out later when it's busy and see what turns up.
Well, you can always make it busy:
yes > /dev/null & yes > /dev/null &
Voila, instant 100% load on both cores. ;-)
On 4/14/07, Florin Andrei florin@andrei.myip.org wrote:
Well, you can always make it busy:
yes > /dev/null & yes > /dev/null &
Voila, instant 100% load on both cores. ;-)
Oh, yeah!
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 : 2211.361 cache size : 512 KB physical id : 0 siblings : 2 core id : 0 cpu cores : 2 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 cx16 bogomips : 4425.46 TLB size : 1088 4K pages clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: ts fid vid ttp [4] [5]
processor : 1 vendor_id : AuthenticAMD cpu family : 15 model : 75 model name : AMD Athlon(tm) 64 X2 Dual Core Processor 4200+ stepping : 2 cpu MHz : 2211.361 cache size : 512 KB physical id : 0 siblings : 2 core id : 1 cpu cores : 2 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 cx16 bogomips : 4425.46 TLB size : 1088 4K pages clflush size : 64 cache_alignment : 64 address sizes : 40 bits physical, 48 bits virtual power management: ts fid vid ttp [4] [5]
Thanks, Florin!
mhr
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.
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.
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Feizhou -
Florin Andrei -
Jay Leafey -
John R Pierce -
John Summerfield -
Mark Hull-Richter -
Paul -
Peter Arremann