Multicore SAT Solver I am trying to solve a 25k clauses 5k variables SAT problem. As it has been running for an hour (precosat) and I'd like to solve bigger ones afterwards, I'm looking for a multi-core SAT-Solver.

As there seem to be many SAT-Solvers, I'm quite lost.

Could anyone point me out the best one for my case?

I'd also be happy if someone could give me the approximate time (if possible).
Have a look at the results from this years SAT 2013 competition. Based on these results, definitely give Lingeling a try. Plingeling is the parallel variant of it.

If you don't need to prove unsatisfiability (perhaps you know the instance is satisfiable, and you just need to know an assignment making it SAT), you could try local search methods, too.