This information was never been listed oficially, but you can find some such details at SPEC SFS pages for tested systems.
For example: 3210 - single dualcore 2.3GHz Intel Xeon(tm) Processor E5220, 3270 - dual dualcore 3.0GHz Intel Xeon(tm) Processor E5240.
But in real life you haven't a reason to know it ;o)