Oh for sure there are cases that might saturate all cores. They're just incredibly rare, even on machines that are working at "100%". The case of web servers is

Oh for sure there are cases that might saturate all cores. They're just incredibly rare, even on machines that are working at "100%". The case of web servers is an interesting one because benchmarks seldom see them actually running at 100% despite putting all of their combined resources at a problem -- there is usually something else synchronously slowing the flow, or a simple bottleneck like Gbps networking. Even on virtualization servers, one generally leaves enough headroom that the machine is nowhere near saturated.