Can your problem be parallelised or broken down into smaller sized problems (such as, utilising symmetry where possible)?

may be you can check your data in hard disk, if your design need more space, just back up your data first, what kind of antenna did you design?

may be you can check your data in hard disk first, if your design need more space, just back up your other data, what kind of antenna did you design? may be you can reduce the frequency plot

may be you can check your data in hard-disk first, if your design need more space, just back up your other data, what kind of antenna did you design? may be you can reduce the frequency plot

may be you can reduce frequency plot

may be you can reduce frequency plot

change mesh density....

Swapnil Narke, mesh density reduction means..??

HFSS-Mesh operation- Initial mesh settings.

Go through this path and change the settings. If your mesh density is high means high resolution  then HFSS will take more time. So that reduce the resolution.

Hi Sounik,

What kind of antenna are you simulating? Simulations which contain effective symmetry planes can be reduced in size by using the appropriate boundary conditions. For example, a patch antenna operating in its fundamental mode has an effective (magnetic) H-wall in the direction of phase change. Therefore, you can cut the simulation in half down this plane and replace with an perfect-H boundary -- this will obviously reduce the simulation size. That being said, caution must be taken to ensure you're using an appropriate boundary, otherwise you'll end up with a nonsensical solution.

Good Luck!

There are two basic ways to reduce simulation time in hfss, but by doing so u will compromise with the exact solution.. 

1. keep the step size large like in place of 0.01 GHz keep 0.1 GHz.....

2. Use small frequency sweep.

use sweep type --> FAST,  frequency sweep --> LINEAR STEP,  use start and stop frequencies according to your requirements , and finally use step size 0.2GHz to 0.5 GHz. and then simulate .. 

Thank You Ganesh Balbhim Waghmare.

same design try to cross verify in CST too .

You can reduce the no. Of meshes in HFSS , or use CST. Or get new version of HFSS 2016. Named Ansys. 16

Reduce step size and meshing by using higher values to see the trend. Later you can simulate with the smaller values to get the accuracy. 

All the best :)

You can reduce the frequency range keeping the same step size which will not degrade the results. Or reduce the step size for frequency increment. If still RAM shortage is there, Then only reduce the number of meshes as it can degrade the results. You need to have a minimum of lambda/10 mesh size for a reliable result.

Manoj Stanley, Could you please suggest me the step to reduce the mesh size ?

keep the step size large and make boundary box as small as possible but the dimension of box must satisfy the far field criteria, it should be taken care of

You can set the mesh size by assigning 'Mesh Operations' (right click on object -> Assign Mesh Operation). Use a minimum length setting to get the results you want. (lambda/10)

This is what happens in HFSS meshing in detail. You can read this to get a clearer picture.

HFSS using convergence in order to get an accurate solution. After creating an initial mesh it starts doing adaptive passes until the desired error residual is achieved. In each stage it refines the mesh and resolves the problem. The resulting S-Matrix is compared to the previous one. The maximum delta is computed in percentage. If the max error found is 3% and you specified Maximum delta S per pass.to be 0.02=2% then it will continue with another meshing and solving. If the max error found is reduced to 1.5% the solution is "converged" and the simulation will stop.

In order to control this process you have a few options:

1) Maximum number of passes - Allows you to stop after several passes. Even if you want faster solution times I recommend not to use this option and set it to 20.

2) Maximum delta S per pass - Allows you to define the desired accuracy for the solution. For example, in many Signal Integrity applications 4% is more than enough.

3) Refinment per pass - for simple problems increase from 20% to 30%. This controls the amount of mesh refignment between passes.

4) Minimum converged passes - I recommend to set it to 1. This allows you to force HFSS to continue more adaptive passes even after it converged.

5) Port accuracy. The default is 2%. This controls the accuracy of the 2D solution on the port. If you are solving ports only (for example to calculate effective lambda for a transmition line) - I recommend to increase accuracy from 2% to 0.3% or even 0.1%.

First you large the step size for the fixed solution frequency and fixed frequency range while simulation finished you can make your step size small for the same setup, solution frequency & frequency range and then simulate then it will take small time so in this way you can get smooth graphs and it will also take the same time.

you can reduce your simulation time by

a) By decreasing step size

b) By unchecking save fields

c) choosing fast,interpolating,discrete type sweep

fast will take lesss ram less time

interpolating moderate

discrete takes more ram more time more accuracy.

initially do simulations with fast or interpolating then lastly go for vdicrete mode

how to reduce mesh size, please give me the answer

Follow the below method attached

Initially, U run the simulation for large step size and select fast sweep mode to reduce the simulation time in analysis set up.

I also have same problem, simulating a design gives error 'out of memory'. Please give idea to sort this error.

First you should select the fast sweep mode and then keep the large step size to reduce the simulation time period.

Hello Permanand Soothar Ravi Dwivedi Akinola S.A Wriddhi Bhowmik Manoj Stanley Srinivas D

Im running simulation in Maxwell 3D, the analysis is taking upto 3-4 hours and not even finishing i need to reduce the time

i read above comments but i didnt find how to select sweep mode, or reduce step size there is no such an option in Maxwell 3D

im using i7 with 16GB Laptop

kindly assist im using Maxwell 14.0

Thanks, Mekala Harinath Reddy for the answer.

Thanks, Mekala Harinath Reddy for the answer.

You need to expand RAM to 32 GB.

If u r comfortable then u can enhance ur systems RAM, otherwise follow above mentioned comments for fast sweep type n larger step size.

Reduce the meshing, if you can get best performances.

I agree with Ahmed Moulay . HFSS has very powerful mesh adaption routines; I have generally found that setting up a loose a mesh as possible (setting up an initial mesh only on curved surfaces) generally gives the best results in the shortest amount of time.