techPowerUp published Bulldozer Core-Count Debate Comes Back to Haunt AMD
A quote from the article:
AMD in 2012 launched the FX-8150, the "world's first 8-core desktop processor," or so it says on the literal tin. AMD achieved its core-count of 8 with an unconventional CPU core design. Its 8 cores are arranged in four sets of two cores each, called "modules." Each core has its own independent integer unit and L1 data cache, while the two cores share a majority of their components - the core's front-end, a branch-predictor, a 2 MB L2 cache, but most importantly, an FPU. There was much debate across tech forums on what constitutes a CPU core.Bulldozer Core-Count Debate Comes Back to Haunt AMD
Multiprocessor-aware operating systems had to be tweaked on how to properly address a "Bulldozer" processor. Their schedulers would initially treat "Bulldozer" core as a fully independent CPU (as conventional logic would dictate), until AMD noticed multi-threaded application performance bottlenecks. Eventually, Windows and various *nix kernels received updates to their schedulers to treat each module as a core, and each core as an SMT unit (a logical processor). The FX-8150 is a 4-core/8-thread processor in the eyes of Windows 10, for example. These updates improved the processors' performance but not before consumers started noticing that their operating systems weren't reporting the correct core-count. In 2015, a class-action lawsuit was filed against AMD for false marketing of FX-series processors. The wheels of that lawsuit are finally moving, after a 12-member Jury is set up to examine what constitutes a CPU core, and whether an AMD FX-8000 or FX-9000 series processor can qualify as an 8-core chip.