14.04, I have Disabled CPU throttling, but installing Atlas says: "CPU Throttling apparently enabled"

My PC is using ubuntu 14.04, and I need install Atlas.

Atlas says: it need to disable CPU throttling, I have done the job to disable it.

cat /sys/devices/system/cpu/cpu{0,1,2,3}/cpufreq/scaling_governor
performance
performance
performance
performance

But when I was running this command to install Atlas:

../configure -b 64 -D c 2400 --prefix=/home/azhen/lib/atlas --with-netlib-lapack-tarfile=/home/azhen/Downloads/lapack-3.4.1.tgz

It says:

CPU Throttling apparently enabled!
It appears you have cpu throttling enabled, which makes timings
unreliable and an ATLAS install nonsensical.  Aborting.
See ATLAS/INSTALL.txt for further information

Can someone help me take a look?

Solution 1:

I am a fairly recent Ubuntu user and not a computer expert and I was having exactly the same problem as you. After some struggling, I managed to avoid the message "CPU Throttling apparently enabled!" and got ATLAS 3.10.2 installed.

The first tip I got in https://sourceforge.net/p/math-atlas/support-requests/859/#f11d, where it basically says that "The only time ATLAS should detect throttling that isn't occurring is when the processors are fixed to run at a lower speed than their maximum speed." My processor was not running at its maximum speed, since I had a BIOS speed limit.

If you have the same problem, look at the maximum frequency allowed in the file /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq. Copy this value to the files for each processor(/cpu/cpu1, /cpu/cpu2 etc). You need to do it as super-user, but before it takes effect, you have to edit the file /sys/module/processor/parameters/ignore_ppc from 0 to 1. More details are given here.

This was still not enough for me and I figured out that I had to edit the files /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq to the same value that was used before. After that, I did not get the boring message any more and ATLAS was successfully installed!

update: I have just gone through this process again and it seems that the real problem is to have the power scaling driver intel p_state enabled. The procedure above will only work if you disable it first. Follow the instructions in here and replace "enable" by "disable" as explained here.

Solution 2:

I followed the Caffe installation guide for ubuntu where it is written that one can install BLAS by

sudo apt-get install libatlas-base-dev