Comment 4 for bug 956753

Sorry for the incomplete report. As my understanding on how atlas works is very limited, I didn't know if you (the packager) added some debian/ubuntu specific compiler options leading to this result. So I asked here first because I wondererd if there maybe was a trivial answer (like setting a specific flag during compilation).

So here is what I did:
disabled CPU throtteling in BIOS
apt-get source atlas
fakeroot debian/rules
installed the package

Open R:

a<-list();for(i in 1:10){a[[i]]<-matrix(rnorm(1e6),1000,1000)} ## create a list containing large matrices
system.time(lapply(a,solve)) ### measure time of inverting 10 matrices

I also monitored the CPU usage using the gnome system monitor and compared with the result using the OpenBLAS library.
The latter uses 100% on all cores.

My hardware specs:
CPU: Intel Core2 Quad CPU Q9400 @ 2.66GHz × 4
RAM: 8GB

Ubuntu 12.04 64bit