The Xeon E5-2600: Dual Sandy Bridge for Servers

LS-DYNA

LS-DYNA is a "general purpose structural and fluid analysis simulation software package capable of simulating complex real world problems", developed by the Livermore Software Technology Corporation (LSTC). It is used by the automobile, aerospace, construction, military, manufacturing and bioengineering industry. Even simple simulations take hours to complete, so even a small performance increase results in tangible savings. Add to that that many of our readers have been asking that we perform some benchmarking with HPC workloads. So reasons enough to include our own LS-DYNA benchmarking.

These numbers are not directly comparable with AMD's and Intel's benchmarks as we did not perform any special tuning besides using the message passing interface (MPI) version of LS-DYNA ( ls971_mpp_hpmpi ) to run the LS-DYNA solver to get maximum scalability. This is HP-MPI version of LS-DYNA 9.71.

Our first test is a refined revised  Neon crash test simulation.

This is one of the few benchmarks (besides SAP) where the Opteron 6276 outperforms the older Opteron 6174 by a tangible margin (about 20% faster) and is significantly faster than the Xeon 5600, by 40% to be more precise. However, the direct competitor of the 6276, the Xeon E5-2630, will do a bit better (see the E5-2660 6C score). When you are aiming for the best performance, it is impossible to beat the best Xeons: the Xeon E5-2660 offers 26% better performance, the 2690 is 46% faster. It is interesting to note that LS-Dyna does not scale well with clockspeed: the 32% higher clockspeed of the Xeon E5-2690 results in only a 15% speed increase.

A few other interesting things to note: we saw only a very smal performance increase (+5%) due to Hyperthreading. Memory bandwidth does not seem to be critical either, as performance increased by only 6% when we replaced DDR3-1333 with DDR3-1600. If LS-Dyna was bottlenecked severely by the memory speed we should have seen a performance increase close to 20% (1600 vs 1333).

CMT boosted the Opteron 6276's performance by up to 33%, which seems weird at first since LS-DYNA is a typical floating point intensive application. As the shared floating point "outsources" load and stores to the integer cores, the most logical explanation is that LS-DYNA is limited by the load/store bandwidth. This is in sharp contrast with for example 3DS Max where the additional overhead of 16 extra threads slowed the shared FP down instead of speeding it up.

Also, both CPUs seem to have made good use of their turbo capabilities. The AMD Opteron was running at 2.6 GHz most of the time, the Xeon 2690 at 3.3 GHz and the Xeon 2660 at 2.6 GHz.

The second test is the "Three Vehicle Collision Test" simulation, which runs a lot longer.

The three vehicle collision test does not change the benchmarking picture, it confirms our early findings. The Opteron Interlagos does well, but the Xeon E5 is the new HPC champion.