It's still running pretty much everything in ring 0 that a traditional monolithic kernel would. All the "complex parts" run in kernel mode. The new WDDM driver

It's still running pretty much everything in ring 0 that a traditional monolithic kernel would. All the "complex parts" run in kernel mode. The new WDDM driver model runs a user-mode driver, but it's still backed by a set of kernel-mode drivers [1], including the "display miniport" driver. As kernels go, it's pretty monolithic. What makes it more like a microkernel is that many of the internal APIs use a message-passing model rather than direct calls. [1] https://msdn.microsoft.com/en-us/library/windows/hardware/ff570589(v=vs.85).aspx https://msdn.microsoft.com/en-us/library/windows/hardware/ff...