I faced the same issue and taking note of what nikhil153 mentioned, did the following fix in line 136 of rapl_device.py: if domain_name_file.readline() == 'package-' + str(socket_id) + '\n': #removed this if "package-" in domain_name_file.readline(): #replaced with this Hope this helps others too! _Originally posted by @venugopalansgr in https://github.com/powerapi-ng/pyJoules/issues/14#issuecomment-2049008761_