If you stay 100% within your own application and don't touch syscalls or libraries then yes they should perform identically (other than other processes using th

If you stay 100% within your own application and don't touch syscalls or libraries then yes they should perform identically (other than other processes using the CPU and I guess maybe default CPU speed settings). In practice, you're going to makes syscalls and use other libraries, which means that the kernel is an extremely important part of the overall performance picture and the design decisions that are baked into those libraries matters.