[petsc-users] CPU selection

[Barry Smith]

On Oct 24, 2011, at 7:20 AM, Jed Brown wrote:

> 2011/10/24 Gong Ding <gdiso at ustc.edu>
> Hi all
> We'd like to buy one more computation node for TCAD simulation.
> The simulation code is based on petsc, 90% of the time spend on linear solver.
> Krylov solvers such as BCGS/GMRES and MUMPS solver are mostly used.
> 
> Now we have two choise, one is based on Intel XEON E5620 (4 Core) and 
> the othre is based on AMD Opteron 6128 (8 Core).
> The tow CPUs are nearly at the same price.
> 
> For sparse linear algebra, you are buying memory bandwidth. In this case, the Xeon has 3 channels of DDR3-1066 for an aggregate bandwidth of 25.5 GB/s where as the 6128 has 4 channels of DDR3-1333 for an aggregate bandwidth of 42.6 GB/s. Note however, that you are probably less likely to fully utilize the bandwidth on the Opteron because it has a deeper NUMA hierarchy. It's probably still faster, but probably not by much. If you get the Opteron, be sure to get a motherboard that supports DDR3-1333 and actually get the fast memory.

  If at all possible, you'll want to see the Streams benchmark numbers in parallel for both of these for comparison purposes.

    Barry