User Forum of Software BASEMENT

Joshua

User

Registered: 2016-12-08

Posts: 3

computation speed

Hello everyone,

I'm running Basement (Baseplane) on Intel(R) Core(TM) i5-4210U CPU @ 1.70GHz with Windows 7. Starting simulations of a flood inundation event with 60000 elements (about 1 m² the smallest) and 60 hours of simulation time, I get runtimes of 10 hours and more. Can you give any advice in how to efficiantly speed up the computation? Are there any parameter settings which could considerably slow down the programm?

Thanks alot for your help!

Best regards,
Joshua

sajjad

User

Registered: 2014-10-01

Posts: 102

Re: computation speed

Dear,

hope you are using parallel computing by using 2 to 3 cores which you can specify in 'Parallel' block. It should improve the speed. Next, reduce result file writing to absolutely essential and same goes for restart file for which you should use very large time step in output block. Run at CFL=1 and if possible cut down the simulation time. There may be marginal improvement if you use Riemann solver 'hll' or 'hllc' in place of 'exact'.

Regards

Stephan Kammerer

Developer

Registered: 2015-03-31

Posts: 67

Re: computation speed

You can define a "SPECIAL_OUTPUT" of type "balance" with balance_values "timestep". This will provide a text file including the computational timesteps and the ID of the timestep limiting element. Like this you can optimize your mesh and get rid of very small elements.

Joshua

User

Registered: 2016-12-08

Posts: 3

Re: computation speed

Thanks alot for the quick response!

Following your advice I'll check my mesh again, but broadening all elements would of course effect the precision of the model.
I'm running Basement in parallel mode using 2 cores (while examining that additional cores wouldn't save much more time).
I was already playing around with the parameter settings, wondering if I had missed something.

So would you think it is normal to get such runtimes with my configurations?

Best regards,
Joshua

maarnold

Advanced_User

Registered: 2014-09-13

Posts: 30

Re: computation speed

Hi Joshua

I did a quick google search on your processor and it seems that your processor "only" has two cores. Using more than 2 cores in parallel mode wouldn't save time or could even increase the computational time (my experience).
A bit more information on parallel computing with BASEMENT can be found here:
Best computing performance with Basement

You could create a coarser mesh and only refine the areas of interest.

Best regards,

Mat