All users are enabled on the Cori KNL nodes to run jobs up to 512 nodes for 2 hours. If you want to run bigger and longer jobs, you can gain access via the below form.
The Knights Landing architecture on Cori is unique in a number of ways from previous platforms at NERSC such as Cori Phase I:
The purpose of this application is to:
In order to complete this form, you will be asked to run your application (using the debug queue) in several different ways on Knights Landing compute nodes. Detailed instructions and example output can be found here.
For more information on profiling, please review information on Performance and Debugging Tools. For information of how to employ and optimize Simultaneous Multithreading (SMT) in your application, please read our website on OpenMP parallelization. Our KNL optimization case studies might also serve as a good reference for what needs to be done in order for getting ready for KNL
Paste your results from the thread scaling study for Haswell (Cori Phase I) and KNL (Cori Phase II) into the text field and click on "Plot Results" to draw a plot.
Paste your results from the MPI vs. thread scaling study for Haswell and KNL into this field and click on "Plot Results" to draw a plot.
Paste your results from the KNL memory mode study into this field and click on "Plot Results" to draw a plot.
Use the following compiler options disable or reduce the vectorization support. Here is a list which describes how you can achieve this with the various NERSC supported compiler flavors. We have created a table with the necessary compile flags:
|Intel||-no-vec -no-simd (and comment out OpenMP SIMD pragmas)||-xCORE-AVX2||-xMIC-AVX512|
|GNU||-march=knl -fno-tree-vectorize -fno-tree-loop-vectorize -fno-tree-slp-vectorize||-march=knl -mavx2||-march=knl|
|Cray||-h vector0 -h nopattern||-h cpu=haswell||-h cpu=mic-knl|
Paste your results from the KNL vectorization experiment into this field and click on "Plot Results" to draw a plot.
Paste your results from the multi-node-scaling experiment into this field and click on "Plot Results" to draw a plot. If you are planning to use the system mainly for capacity workloads, please provide a weak scaling study. If you plan to use it for capability workloads, please provide a strong scaling study. If you plan to do both, please provide both. In any case, please scale the problem up to as many nodes as you are going to use later on with a representative local problem size.