Sometimes when modelling large PLAXIS project files with e.g. a lot of phases or a lot of steps, Plaxis may indicate that there is not enough disk space available:

• Since PLAXIS 2D AE and PLAXIS 3D (including PLAXIS CONNECT Edition V20, V21, V22, and Version 2023 and later) all unsaved data are stored in the Windows temporary folder (TEMP). By default, this is located on the primary disk drive in the user profile. Only when explicitly saving the Plaxis project data, this data will be stored in (i.e. moved to) the actual save location.
• Next to that, during a calculation, all intermediate results (step files) are kept in the same location, and only when the phase calculation has finished, will the data be post-processed by keeping the number of result step files as specified in the Max number of steps stored parameter for that phase, and deleting the other data.

When this issue of not enough free disk space appears, you can use one of these available workarounds:

1. Store the Windows TEMP folder on a disk with larger space. To do so, open Windows’s Control panel, and go to Control panel > System and Security > System > Advanced System settings, and in the tab Advanced, open the Environment Variables... window. Here you can set the current user’s variable TEMP to the desired new location. Note: the user might need to have administrator rights to perform this.
2. For projects with a lot of phases, it may help to not calculate the entire Plaxis project in one go, but to calculate a part of the Plaxis project, save the model, and calculate the remainder of the Plaxis project. By saving the data halfway the calculation phases, the data stored in the Windows TEMP folder will be moved to the final save location, freeing up disk space for the Windows TEMP folder.
   Note that this can be automated using the commands runner,e.g.
   calculate Phase_1
   save
   calculate Phase_2
   save
   calculate Phase_3
   save
   etc.
3. For dynamic calculations, only the data for a step is stored, not for a dynamic substep. If not all intermediate results need to be kept, or if not for each step a data point for the curve points is needed, the number of additional steps (Max steps) can be reduced. Please make sure to simultaneously increase the number of dynamic substeps, such that the product Max steps * Number of sub-steps is kept constant, see this article: Time step used in dynamic calculation
4. There is an option to store the intermediate calculation result data in a different location. This is especially useful when for instance running a long dynamics calculation with a lot of steps in a single phase and the above-mentioned options do not give the solution for enough free disk space. To change the location of this intermediate calculation data, the program needs to be launched with an additional parameter, called --CALCDIR.
   
   Example: To start PLAXIS 3D Version 2024 from the default installation folder while setting the calculation folder (CALCDIR) to D:\PlaxisCalc:

   "C:\Program Files\Seequent\PLAXIS 3D 2024\Plaxis3DInput.exe" "--CALCDIR=D:\PlaxisCalc"

   For PLAXIS 2D 2024 this would be:

   "C:\Program Files\Seequent\PLAXIS 2D 2024\Plaxis2DXInput.exe" "--CALCDIR=D:\PlaxisCalc"

   This can be used in e.g. a DOS command, in Windows Start menu's Run..., run from a batch file (*.bat), or be defined in a Windows shortcut.

Please be aware when moving the folder where the intermediate (calculation) results are stored (options 1 and 4) to a disk with less read/write speed, it may lead to a longer calculation time.

Note: default installation folders are located in:

• PLAXIS 2D/3D Version 2023 and later, the installation folder is by default located inside: C:\Program Files\Seequent\
• PLAXIS 2D/3D CONNECT Edition V20/V21/V22: C:\Program Files\Bentley\Geotechnical\