Ansys HPC licensing

This page provides guidelines on how Ansys HPC licensing requirements are calculated. The formula is provided to calculate the required number of HPC licenses running a single simulation or multiple concurrent parametric calculations. 

Authored by Lito Yap

Notes:

• 1 parametric variation is free from 1 solve license. Each parametric variation beyond that requires 8 HPC licenses.
• 1 solve allows running up to 4 cores for each variation. Each core beyond that requires 1 HPC license.
• Computations are based on 1 solve license sharing to run concurrent parametric variations / simulations. 

Ansys HPC workgroup computation

Formula

(# of variations - 1 solver) * 8 HPC/variation + (# cores or SMs / job - 4 (free from solve) * 1 HPC/core or SM * # of variations)

Ansys HPC pack computation

A different computation will be used when calculating HPC packs. Based on the mapping of CPU cores/GPU SMs vs HPC packs (running a single simulation with multiple cores/SMs) as shown in the image. 

Formula: 

ParallelCount = # variations * (# cores or SMs - 4 free)

If ParallelCount > 0:
   If ParallelCount > 8:
       IntermediatePacks = CEILING( LOG2(ParallelCount / 2) / LOG2(4) )
   else:
       IntermediatePacks = 1
else:
   IntermediatePacks = 0

NumPacks = IntermediatePacks + # variations

If NumPacks >= 2:
   NumPacks = NumPacks - # solvers

Examples

Example: 8 parametric variations at 4 cores each

• Variations: 8 
• Cores: 4

HPC workgroup license computation

HPC = (8 - 1) * 8 + ((4/job - 4) * 1 * 8)
HPC = 7 * 8 + (4-4)*1*8
HPC = 56 + 0*1*8
HPC = 56

HPC Pack license computation

ParallelCount = 8 variations * (4 cores – 4 cores for free) = 0
IntermediatePacks = 0
NumPacks = 0 + 8 = 8
NumPacks = 8 – 1 solver
HPC Packs = 7

Example: 16 parametric variations at 16 cores each 

• Variations: 16
• Cores: 16

HPC Workgroup license computation

HPC = (16 - 1) * 8 + ((16/job - 4) * 1 * 16)
HPC = 312

HPC Pack license computation

ParallelCount = 16 variations * (16 cores – 4 cores for free) = 64
IntermediatePacks = 4
NumPacks = 4 + 16 = 20
NumPacks = 20 – 1 solver
HPC Packs = 19

Open the License estimation utility in the Lumerical GUI's Resources for an estimate of the license consumption based on your resources configuration.

See also

List of Lumerical license features by product

Resource configuration elements and controls  

Compute resource configuration use cases