[LBo] Processor speed

[Allen Farley]

Troy wrote:
> I have a HP Pavilion ze4125 lap top, and I just filled the memory to
> capacity (1 gig), but the computer still seems to run slow.  According to
> HP's web site, the processor is an AMD Athlon Xp 1600+, which runs at
> 1.4GHz.  However, when I run the cat command on the /proc/cpuinfo
> file, I
> receive the following output:
>
> troy at troy-laptop:~$ cat /proc/cpuinfo
> processor       : 0
> vendor_id       : AuthenticAMD
> cpu family      : 6
> model           : 8
> model name      : mobile AMD Athlon(tm) XP 1600+
> stepping        : 0
> cpu MHz         : 662.575
> cache size      : 256 KB
> 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 sep mtrr pge mca cmov
> pat pse36 mmx fxsr sse syscall mp mmxext 3dnowext 3dnow up ts fid vid
> bogomips        : 1325.90
> clflush size    : 32
>
> If I'm reading this right, the cpu speed is 662 MHz, not the 1.4 GHz it
> should be.  I'm running Ubuntu 7.04.  Any thoughts or ideas?
>   
I do know that laptops can vary their CPU frequency to conserve battery 
power, this may be what you are seeing. Here's some snippets from:

http://en.wikipedia.org/wiki/Athlon

Mobile Athlon XPs (/Athlon XP-M/) are identical to normal Athlon XPs, 
apart from running at lower voltages, often lower bus speeds, and not 
being multiplier <http://en.wikipedia.org/wiki/CPU_multiplier>-locked. 
The lower V-core rating caused the CPU to have lower power consumption 
(ideal for battery-powered laptops) and lower heat production. Athlon 
XP-M CPUs also have a higher-rated heat tolerance, a requirement of the 
tight conditions within a notebook PC.

The Athlon XP-M replaced the older Mobile Athlon 4. The Mobile Athlon 4 
used the older /Palomino/ core, while the Athlon XP-M used the newer 
/Thoroughbred/ and /Barton/ cores. Some specialized low-power Athlon 
XP-Ms utilize the microPGA socket 563 
<http://en.wikipedia.org/wiki/Socket_563> rather than the standard 
Socket A.

[***Notice this part***]

The CPUs, like their mobile K6+ 
<http://en.wikipedia.org/wiki/AMD_K6-III> predecessors, were also 
capable of dynamic clock adjustment for power optimization. When the 
system is idle <http://en.wikipedia.org/wiki/Idle>, the CPU clocks 
itself down through a lower bus multiplier and also reduces its voltage. 
Then, when a program demands more computational resources, the CPU very 
quickly (there is some latency) returns to intermediate or maximum speed 
to meet the demand. This technology was marketed as "PowerNow! 
<http://en.wikipedia.org/wiki/PowerNow%21>". It was similar to Intel's 
SpeedStep <http://en.wikipedia.org/wiki/SpeedStep> power saving 
technique. The feature was controlled by the CPU, motherboard BIOS 
<http://en.wikipedia.org/wiki/BIOS>, and operating system 
<http://en.wikipedia.org/wiki/Operating_system>. AMD later renamed the 
technology to Cool'n'Quiet 
<http://en.wikipedia.org/wiki/Cool%27n%27Quiet>, on their K8-based CPUs 
(Athlon 64 <http://en.wikipedia.org/wiki/Athlon_64>, etc), and 
re-imagined it for use on desktop PCs as well.



-- 
Allen Farley
drax946[at]gmail.com
Linux User #437334