[petsc-users] Problem with SNES

[Milan Mitrovic]

well... I added matrix elements by row (~150 nonzero elements) but I
have 7.5k rows per processor... I know the exact nonzero pattern and I
preallocated the storage so it is not that... and its all done
locally... I couldn't insert blocks because there is no common
structure to the nonzero pattern of different rows...

so to me it seems that creating the matrix like this should be fast...
computing the values took <3 seconds but the setvalues routine took
more than a minute!