Workstation comparison

Does anyone know of a good comparison (that wasn’t sponsored by a competing company) of workstations for high-end computation, modeling, simulations, etc. (eg. Sun Blad 2500 vs. HP c8000 vs. Sun Java w2100z etc).

Does anyone know of a good location for literature about how to interpret benchmarks and performance metrics (I/O bandwidth, memroy bandwidth, etc.)?

Thanks!