Seems I have found the issue , was CFLAGS /proc/cpuinfo => processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 4 model name : Intel(R) Xeon(TM) CPU 3.00GHz you need CFLAGS="-march=nocona -O2 -pipe -fomit-frame-pointer" I had CFLAGS="-march=k8 -O2 -pipe" catam