Simultaneous Multi-threading (S.M.T.) or Hyper-Threading, as Intel likes to call it, is something that has been on the company"s chips for over 20 years at this point. Team Blue first introduced it in 2002 on its Xeon range of CPUs and then debuted the same on the desktop lineup with Pentium 4, later in the same year. This was the time of Windows XP, and Intel has continued to use this tech up until now, with optimizations along the way.
In case you may not be aware of the benefits of it, Hyper-Threading technology (HTT) allows a physical core to execute more than one instruction in the pipeline. This parallel processing essentially improves the multithreaded performance of a hyperthreaded chip as a single physical core on the chip is able to act like two via its two hyper-threaded logical cores. This does not however imply that one hyper-theaded physical core will be as good as two physical cores though. It only leads to better performance compared to one physical core, and two real cores are still faster as it has more resources at its disposal (like cache, Integer units, Floating point units) than a single real core.
AMD tried its slightly altered version with CMT (Clustered Multi-threading) with Bulldozer but it proved to be a massive failure, which is why it borrowed a page from Intel and Zen (Ryzen CPUs) picked up SMT instead.
Despite all the success Intel has enjoyed with HTT though, it seems the company is looking to part ways from it on next-gen desktop and laptop parts.
The latest leak shows a Task Manager screenshot which apparently is that of Lunar Lake, Intel"s 16th Gen mobile processor, on its early A1 stepping. Indeed what is the most interesting thing about it is the number of (physical) cores and logical cores Windows picks up as both of them are read as eight. This means there appears to be no HTT active on this part at least.
Also, Lunar Lake may not be the first or only time Intel will seemingly ditch Hyper-Threading. An alleged snapshot of an Intel document also apparently shows missing HTT on the desktop side Arrow Lake-S as well.
While Intel"s E-cores (Efficient cores) already do not have hyper-threading, it looks like the company will be killing it off on its traditional Performance cores (P-cores) as well.
Source: Xzair (Zhihu) via HXL (Twitter/X) |yuuki_ans (X/Twiiter)