For server hardware we recommend generic X86 64 servers, e.g. Supermicro with 2x CXeon 56xx and 144GB RAM. The dual socket Xeon 56xx series is a better deal in terms for price performance than the 4 socket Xeon 75xx series. As X86 64 is today' s principal server platform, our code is specially optimized for this, for example better than for SPARC, on which it also runs.
Database files are preferably to be kept on SSD's, for example a configuration of 4x 256G SSD and 4x1TB hard disk is practical. The SSD's can be run in software RAID 5. Software RAID is usually faster than hardware.