From the very beginning of computer epoch, opinion was that parallelization and everything connected to computers needs to be scaled to the second power, although it doesn't matter if you have 1, 2 or even 73 cores. In any case, everything will work properly, unless we are talking about some old version of synthetic benchmark programs that doesn't recognize processor with odd number of processors. If one worker will do the job for 24h, two will do for 12h and for three workers you can guess by yourself. This analogy goes for multi-thread software which can recognize multi-core processors.