En alternative, il y a iStat Menu, plus complet, mais payant.
L'auteur de Menu Meters annonce que son soft est pour l'instant incompatible avec OS X Capitan :
Due to new Apple-enforced code signature restrictions, MenuMeters is not compatible with the OS X 10.11 "El Capitan" public beta. Although the restriction is similar, this is not directly related to 10.11's "System Integrity Protection" (SIP, aka "rootless") feature and disabling SIP has no effect on MenuMeters.
Unless Apple makes the signature restriction optional, it is not clear that MenuMeters in its present form can ever be made compatible with OS X 10.11.
In the meantime I can only suggest that you do not install 10.11 if you wish to use MenuMeters.
Source
Un portage pour El Capitan a été mis à dispo par un amateur japonais http://member.ipmu.jp/yuji.tachikawa/Me ... ElCapitan/