[ceequof]

  The fileserver tier consists of pairs of Dell R720s 
  running in active/standby configuration. Each pair is 
  largely similar to the single pair of machines that the 
  old Pages infrastructure ran on.

http://www.dell.com/us/business/p/poweredge-r720/pd

Two Xeon E5-2600s per machine.

[ChiperSoft]

The ES-2600 series comes in 4 to 12 cores, so that's still a pretty wide range of compute power.