They are all Intel Xeon setups with HP SANs. Some of our servers on older zones (A and B) in London and SLC use Xeon E5500 but all of our other locations use Xeon E5600.
What disk do we use on the Cloud Servers?
AlMost all of our VPS backend servers operate on SANs totaling up to 1200GB each and running in RAID 10 so that this SAN is mirrored in the event of disk failure.