Our current host hardware is dual processor, quad core Xeon 5620 (2.4GHz) with 72GB RAM, and dual processor, hex core Xeon E5645 (2.40GHz) with 96GB RAM. Storage is provided either by a SAN utilising twenty 1TB drives running in RAID6 with two hot spares, or eight local 1TB drives running RAID10.
Our current SAN hardware is dual processor, quad core Xen 5520 with 12GB RAM, with a battery-backed Adaptec 54225 for I/O.
All servers have redundant power supplies plugged into a UPS, which in turn are plugged into multiple power circuits to minimise impact of power issues. All hosts have redundant network interfaces and we have redundant network switches to ensure maximum availability.