dual core and cool -n- quiet

[marko]

I wanted to find out if I'm going this right, I want my Abit AN8 Ultra
board which has a A64 X2 3800 dual core to run with cool-n-quiet.
I'm using the 2.6.14-1.1656_FC4smp kernel

I was trying to use cpuspeed it wasn't seeming to throttle
the cpus by load but then what I decided to do was
removed cpuspeed from the services list by using the chkconfig
command and just do this:

1. put in the /etc/rc.d/rc.local file:

modprobe cpufreq_ondemand
echo "ondemand" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo "ondemand" > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor

I figure you have to do the echo twice since there's two scaling_governor files.

After I did this, I found that my cpuinfo_cur_freq file would sit
at 1000000 when the systems idle and then go up to 2000000 when
busy. I tested this by starting up glxgears and noticed cpuinfo_cur_freq
went up to 200000 for both cpu 0 and 1.
That seems ok now. But one thing, somewhere I was reading there's
a governor called "conservative" that's recommended for use with AMD64
but I don't see this one listed in the scaling_available_governors file,
does this one exist anymore?

One more thing, I don't quite understand why the /proc/cpuinfo file
always shows 2000 MHZ for both cpus but the cpuinfo_cur_freq seems
to show the throttled (current) speed. Doesn't the /proc/cpuinfo frequency
listing change when the cpu changes speed?
thanks
Mark

[vinu]

I'm using an Athlon64 X2 4200+ with FC4 and kernel 2.6.15 on an Asus A8V Deluxe motherboard and cool'n'quiet works fine for me.

In the kernel, I enabled the following --
Power management options > CPU Frequency Scaling
Default CPUFreq governor to "userspace"
AMD/Opteron/Athlon64 PowerNow! as a module.

Cpuspeed works fine with these settings.

Originally Posted by marko

One more thing, I don't quite understand why the /proc/cpuinfo file
always shows 2000 MHZ for both cpus but the cpuinfo_cur_freq seems
to show the throttled (current) speed. Doesn't the /proc/cpuinfo frequency
listing change when the cpu changes speed?
Mark

I've noticed similar behaviour too.... /proc/cpuinfo always seems to show the maximum rated speed of the processor and not the actual throttled speed.

--Vinu.

[fozner]

The cpuinfo_cur_freq must be a new implimentation for dual CPUs. I am using Fedora Core 4_64 with a single CPU and /proc/cpuinfo always shows the current clock speed.

[jeremyreed]

Originally Posted by fozner

The cpuinfo_cur_freq must be a new implimentation for dual CPUs. I am using Fedora Core 4_64 with a single CPU and /proc/cpuinfo always shows the current clock speed.

Ditto here as well, I currently have 7 amd64 single core(venice,san diego) processors running fc4 and proc/cpuinfo always returns the correct frequency. I have even dabbled with the asus auto overclocking utilities in my bios(a8n-sli premium), and the overclocked frequencies do indeed show up in cpuinfo.

Im sure this is a case of new hardware and the need for the bleeding edge software to catch up to it.

[marko]

something else interesting, when I run glxgears to give the
cpus some work, the dual core cpu frequencies stay at
2009.474 for both cpus in the /proc/cpuinfo
but the bogomips rating on cpu 0
goes from it's idle value of 2011 to 4023. So I do see
the bogomips # changing at least for the cpu0 (which is
actually kind of weird, I thought the intent of bogomips
was to be measured at startup time and NOT change
dynamically)
Mark

[jeremyreed]

Originally Posted by marko

something else interesting, when I run glxgears to give the
cpus some work, the dual core cpu frequencies stay at
2009.474 for both cpus in the /proc/cpuinfo
but the bogomips rating on cpu 0
goes from it's idle value of 2011 to 4023. So I do see
the bogomips # changing at least for the cpu0 (which is
actually kind of weird, I thought the intent of bogomips
was to be measured at startup time and NOT change
dynamically)
Mark

The bogomips number is, for the most part, worthless and would not change values from start-up unless your processor changes frequency after startup(cool&quiet). So bogomips does change dynamically, but most people don't realize it as there running processors that do not scale dynamically.