Nah, dosbox (and of course anything that runs inside it) is single threaded. Seriously, 4 cores on a mobile device, with software written the way it is today, is completely superfluous. Even on my workstation most cores are idle unless I'm compiling.
3 of the 4 cores on my desktop lie idle most of the time, too, even in multithreaded apps. But that's not the fault of the CPUs, but rather, the dev tool and code suppliers. When industry finally understands that apps need to be multiPROCESSOR aware, and not just multithreaded, we'll see some advances... even in mobile.
I dream of a multicore tablet running high-demand music production software...
