[petsc-users] slepc eating all my ram

[Jose E. Roman]

> El 15 jul 2016, a las 19:12, Simon Burton <simon at arrowtheory.com> escribió:
> 
> Hi,
> 
> just like this?
> ./ex3 -eps_nev 1 -eps_type power -n 65536 -info
> 
> I still see:
> [0] STSetUp(): Setting up new ST
> 
> and that's when memory usage reaches to 192GB and the machine can't take it.
> 
> I don't understand why the default behaviour creates a spectral transform 
> object that then needs so much memory.
> 
> thanks,
> 
> Simon.

The default spectral transformation (STSHIFT) will allocate just one vector. At which exact point are you seeing that it allocates a bunch of vectors?

Is this the unmodified ex3.c? Or did you change anything like EPSSetOperators(eps,A,B) ?

Do you get the same behaviour with the original ex3 with the same problem size?

Do you have the same problem with a smaller problem? (half size, say)

Jose