want to disable hyperthreading but there is no option in bios for that

[SY3]

i7-8550 model
laptop lenovo ideapad 520

 

[RememberThe5th]

You might only do that via setting afinity in Task manager on Details tab, by right clicking and assigning the cores, other way i really don't know, if the bios is hard locked, that might be the only way.

 

[Traditore]

Laptop BIOS ususally does not allow those kind of changes and has limited tweakability. As Robert Ban stated you can set desired number of cores for a certain application from Windows.