In the server market, there are chips that can run up to eight threads simultaneously, like the IBM Power9 and the Oracle SPARC M8. So far, we haven't seen consumer chips that can execute more than two threads on a single core but it appears the AMD Zen 3 architecture will change that.
WCCF Tech picked up a rumor that Zen 3 will have SMT4, a feature that will enable processors to run four threads on a single core.
As CPU microarchitectures become more complex and as the cores get bigger and bigger some parts of the pipeline grow underutilized and inefficiencies are bound to inherently show up whilst existing ones could grow more exaggerated. This is why SMT makes sense to begin with, and enabling the design to take advantage of these inefficiencies and underutilized resources by executing additional threads per core may be the right solution, if done right and not at the expense of single threaded performance.If the rumor is accurate, it will be interesting to see how these quad-threaded cores will perform. Perhaps the server market will benefit most from this.