CPU benchmarks available online mostly focus on desktop apps/games and rarely on serial/parallel numerical kernels, specially sparse ones (e.g., MatMult). Some benchmarks like NAS/SciMark exists but are rarely used by popular benchmarking sites on lastest/greatest CPUs.
When it comes to codes that use sparse/dense numerical libraries such as PETSc/ScaLAPACK how does one decide which machine to buy/use specially w.r.t. to multicore performance? E.g. would I be better off with an AMD FX8350 or a Intel Core i7-3770K as my Desktop or should I request allocation on a Xeon or Opteron based cluster, specially for small/medium (i.e., less than 4000 cores) type jobs where one has more options.
I know from personal experience that Intel chips have performed significantly better in the last few years but what about the latest AMD stuff?
EDIT: I am specifically interested in PETSc's MatMult kernel (for unstructured FE matrices) which I have been told is memory bound. Performance in terms of percentage of peak FLOPS using all cores I think would be useful.