Skylake node specifications
Each Skylake node has 2x Intel Xeon Gold 6126 CPUs providing the below features.
- Two Intel Xeon Gold 6126 processors, 2.6GHz with 12 cores (24 cores per node)
- 192GB DDR4 memory (8GB per core) via 6 memory channels per CPU socket
- 3 UPI links between processors
- support for AVX512 instructions - eight 64-bit double-precision floating point numbers
The new Skylake nodes can be used through either the Interactive Test and Development (ITD) zone (1 node) or through the batch service (16 nodes available).
For comparison the Ivybridge node specifications are:
- Two Intel Xeon E5-2650v2 processors, 2.6GHz with 8 cores (16 cores per node)
- 64GB, 128GB and 512GB DDR3 per node via 4 memory channels per CPU socket
- 2 QPI links between processors
- support for AVX - four 64-bit double-precision floating point numbers
The performance of the Skylake CPUs has been tested with the HPL Benchmark and results have compared with the existing Ivybridge compute nodes available on Balena. The plot shows that on a node-to-node comparison, between a 16-core Ivybridge node and a 24-core Skylake node, HPL is 3.5 times more performant. On a core-to-core basis, the Skylake nodes HPL is about twice as performant. This increase will be due to the additional memory channels, increased vector width of the AVX512 instruction set and, just for the node-to-node comparison, the additional number of cores available.
For scaling comparisons, the relative performance starts to dip at 8 nodes and is more noticeable at 16 nodes.
Software on Skylake
We are creating a new software modules tree specifically for the Skylake nodes. The Intel Compilers/MPI/MKL, MATLAB, Ansys applications and tools are ready to use. For the other scientific applications, we will explore whether porting to skylake provides significant benefit.