Platform Evaluation (slightly offtopic)

[Chris Greer]

I am now faced with the problem of testing a new hardware
platform and determining how it stacks up against current
hardware.  We run a mixture of Sparc and X86 machines where
I work.  

Can anyone suggest a site that can help me get good benchmarks
for CPU comparisions (We need to evaluate the an application that
benefits from greater clock speeds, and something that benefits more
from SMP machines).  We also need to benchmark I/O subsystems.

Before, we used some basic test like prime number calculations
to stress CPU, and something like bonnie++ for disk I/O, but
we are looking for something that may end up being a little more
unbiased as far as CPU architecture (most prime number code
have highly optimized routines for X86 vs. Sparc Vs. Alpha).

Can anyone point me to resource or pointers for this?

Thanks,
Chris G.