Matthew Russell. “What Is Darwin (and How It Powers Mac OS X)”. O'Reilly Media. 2012年9月30日閲覧。 quote: "The tightly coupled nature of a monolithic kernel allows it to make very efficient use of the underlying hardware [...] Microkernels, on the other hand, run a lot more of the core processes in userland. [...] Unfortunately, these benefits come at the cost of the microkernel having to pass a lot of information in and out of the kernel space through a process known as a context switch. Context switches introduce considerable overhead and therefore result in a performance penalty."
