Plaxis 3d Cloud Computing

Dear Cory,

PLAXIS is implemented and tested to work on native Windows OS in a physical PC. However, it should be possible to be used in a virtual machine. 

Note that virtual machine do apply special settings when it comes to visualisation (to make the remote communication faster). But running a calculation on a virtual machine should be fine. Be aware that since we do not test and support running PLAXIS on a virtual machine any issues that may arise need to be handled via a Service Request: https://apps.bentley.com/srmanager/ProductSupport

With regards to computer specifications, all our recommendations we provide are based on single desktop computers with a natively running Windows 64-bit environment (Windows 10/11), since this is what we design the software for and run all our tests on. The system requirements are mentioned here: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45417/system-requirements---plaxis

 To get quick operations in the program:

• make sure the Windows TEMP is stored on a fast disk, e.g. an SSD. During the calculations, the calculation will need to read and write a lot of data so having a fast drive will help overall for the calculation; 
• storing the final data on a normal hard drive does not influence the calculation time: only when you tell PLAXIS to save the data, the data from the Windows TEMP folder will be moved to the final save location; 
• have enough RAM. For models up to 500,000 elements not doing dynamic calculations, 16 GB should work. For larger models, get at least 32 GB. Only when you have models with roughly more than 1 million elements 32 GB RAM would be required; 
• For visualization, get a recent (gaming) graphics card that supports OpenGL 2 or higher with at least 1 GB of dedicated, not shared, RAM. Preferably from NVIDIA; Note that the Finite Element calculation does not use the graphics card to execute the calculations, this is still all done on the CPU;
• From our benchmarking, we do not see a conclusive speed increase for all kinds of calculation types (Plastic, Consolidation, Dynamics, etc.) in the calculation when you have more than 8 cores; 
• Note that we do not use hyperthreading, but PLAXIS will utilize all physically available cores. If the processor uses hyperthreading, this is not used. What hyperthreading does, is that it splits a core usage into two virtual cores. For a PLAXIS calculation, this means that it will try to use 1 at 100% and the other at about 20% (this is managed by Windows and the processor architecture). Then for the Plaxis calculation, the performance of the first one drops a bit too, since one processor cannot be used for 120% (so to run 120% of calculation operations per second). So, the total performance drops a bit too. In general, for a PLAXIS calculation, this runs slower than using the e.g. 4 physical cores to the max, compared to a setup with 4 hyperthreaded cores (8 logical cores). 
• And of course, a faster CPU will mean faster calculations.  

If you need to make a choice between more CPU cores or faster CPU cores, I would go for the faster cores if your main concern is the PLAXIS calculation speed. We have seen once you have at least quad-core processors, you benefit more from a faster CPU than from more cores.

PLAXIS does not enforce limits on the number of items in a 3D calculation, but of course, the more elements you have, the more memory the program needs, and then you can run into hardware limitations.

Of course, this is the experience we have with the current program.

See more details here:

• Hardware: https://communities.bentley.com/products/geotechnical1/w/wiki/45817/multicore-cpu-and-32-64-bit
• Setting up phases efficiently: https://communities.bentley.com/products/geotechnical1/w/wiki/45816/is-plaxis-3d-enabled-for-multicore
  includes info about running parallel phases simultaneously 

Plaxis does offer certain courses. However, they are prohibitively expensive (€200 for online and €2000 for in-person courses). If possible, arrange for your business to organize a training session, or perhaps someone in your firm has already attended one from www.networklondon.co.uk/. If you can get your hands on them, the course notes and slides are quite beneficial! Another possibility is to experiment with different Geotech FEA programs. Because Adonis is a free, open-source FEA, it may be beneficial to master the fundamental ideas of meshing, constructing geometries, and applying necessary parameters.

When it comes to the calculation speed increase from running on a VM versus a powerful in-house workstation, it depends on the complexity of the analysis. Generally speaking, the more cores and RAM available, the faster the analysis can be completed. In this case, the VM with up to 96 vCPUs and 1 TB of RAM will be able to process more data than the in-house workstation with 4-cores 4.1 GHz processor and 64 GB RAM. However, the processing speed per CPU can be slower on the VM (max 3.5GHz) than the in-house workstation, so the calculation speed may be slower overall. For more professional details, I would recommend to reach out to a cloud consultancy. The guys from there will definitely help you.

Adonis is only for 2D analyses. Most of the challenges in heavy numerical modelling come from 3D modelling. Still, the application of cloud computing is necessary.