eap authentication and cpu utilization

Simple authentication with login/password can be handled in large numbers with a recent cpu and freeradius. . EAP authentication on the other hand requires a great amount of cpu processing. Therefore I have a simple(?) question: Did someone already calcute the theoretically maximum number of eap authentications per second, that a recent x86 cpu is able to handle? Or did someone some practical research on that issue? Norbert Wegener