# Error while running simulations with IDAKLU solver and "dimensionality: 2" on Windows using the latest PyBaMM version

**URL:** <https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240>\
**Category:** General\
**Created:** [18 March 2025 04:25 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240 "2025-03-18T04:25:47Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![appana.3](https://avatars.discourse-cdn.com/v4/letter/a/b782af/32.png) [@appana.3](https://pybamm.discourse.group/u/appana.3)\
**Post date:** [18 March 2025 04:25 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240/1 "2025-03-18T04:25:47Z")

</div>

Hello,

Find below a MWE of the problem I have. When I run this, I get the error shown!

```auto
import pybamm
options = {"dimensionality": 2, "current collector": "potential pair"}
model = pybamm.lithium_ion.DFN(options=options)
parameter_values = pybamm.ParameterValues("NCA_Kim2011")
experiment = pybamm.Experiment(
    [
        (
            "Discharge at C/100 for 1 hours or until 2.5 V" # Discharge experiment
        )
    ]
)
solver = pybamm.IDAKLUSolver()
sim = pybamm.Simulation(model,parameter_values=parameter_values, solver=solver,experiment=experiment)
sim.solve()

```

> MemoryError: Unable to allocate 13.8 GiB for an array with shape (43002, 43002) and data type float64

I was able to run this simulation with the prior 25.1 release on Windows and with the current release using WSL. How do I fix this?

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<div class="post-metadata">

**Author:** ![appana.3](https://avatars.discourse-cdn.com/v4/letter/a/b782af/32.png) [@appana.3](https://pybamm.discourse.group/u/appana.3)\
**Post date:** [20 March 2025 04:47 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240/2 "2025-03-20T04:47:02Z")

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Hey everyone,

Any suggestions on this?

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<div class="post-metadata">

**Author:** ![appana.3](https://avatars.discourse-cdn.com/v4/letter/a/b782af/32.png) [@appana.3](https://pybamm.discourse.group/u/appana.3)\
**Post date:** [30 March 2025 14:50 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240/3 "2025-03-30T14:50:25Z")

</div>

Bumping it back up! Please provide some suggestions

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<div class="post-metadata">

**Author:** ![Marc](https://avatars.discourse-cdn.com/v4/letter/m/8dc957/32.png) [@Marc](https://pybamm.discourse.group/u/Marc)\
**Post date:** [31 March 2025 13:26 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240/4 "2025-03-31T13:26:23Z")

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@appana.3, you can reduce the memory footprint by decreasing the number of spatial points in the PDE mesh. For example,

```python
var_pts = model.default_var_pts
var_pts['x'] = 5
var_pts['y'] = 5
var_pts['z'] = 5

sim = pybamm.Simulation(
    model,
    parameter_values=parameter_values,
    solver=solver,
    experiment=experiment,
    var_pts=var_pts,
)

```

reduced the number of equations by 3.6x.

---

<div class="post-metadata">

**Author:** ![appana.3](https://avatars.discourse-cdn.com/v4/letter/a/b782af/32.png) [@appana.3](https://pybamm.discourse.group/u/appana.3)\
**Post date:** [31 March 2025 15:41 UTC](https://pybamm.discourse.group/t/error-while-running-simulations-with-idaklu-solver-and-dimensionality-2-on-windows-using-the-latest-pybamm-version/240/5 "2025-03-31T15:41:32Z")

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Hello @Marc ,

Thank you for your response. I understand that I can reduce the number of equations by reducing the spatial points in the mesh.

Is there a major change in the latest 25.1 release that prevents me from running this simulation, while I was able to run it on a prior 25.1 release?