I have disabled hyper-threading, on my mid-2015_15-inch_Retina_MacBook-Pro, which normally has a 4th-generation mobile CPU, with four-physical-CPU-“cores”, and four-virtual .
I disabled the hyper-threading feature, to thwart the Meltdown, Spectre-variants, ZombieLoad, and SWAPGS hardware CPU-design-flaws — this incurs, an up-to-40%, performance, hit .
How many CPU-“cores”, do I have, when the Mac’s Hyper-threading is disabled ?
By disabling hyperthreading you are disabling your 4 virtual cores and thus diminishing your processors performance.
If you are only downloading software from the Apple store or trusted vendors you could re enable hyperthreading as the exploits begin with malicious software.