[philippose]

Hello,

Quick question.... is it normal to see large differences in simulation convergence, and significant differences in the results between a 32bit and 64bit run of the same case using simpleFoam??

The 64-bit simulation was run on an AMD X2 (but using only one processor), and the 32-bit version on an Intel Quad-Core (but with OpenFOAM compiled without the WM_64=on option... and again using one processor).

The 64-bit simulation has convergence values at around 760 iterations, which are comparable to those seen at around 1600 iterations on the 32-bit simulation

Moreover.. the results are disturbingly different.

I use the AMG solver for pressure, and the PBiCG for the other fields.

I am not 100% sure anymore if both the systems use the exact same version of OpenFOAM, though both use the OpenFOAM-1.4.1 release (one could be a development release from the Powerlab ftp).

Hoping for an explanation.....

Philippose