The issue has already been mitigated on a hardware level starting with the 8th generation of processors.
If you have an older processor that is affected, you can check to see what firmware updates are available on the Intel site to address the issue. It is also recommended you keep all software (the Operating system and any 3rd party programs installed) up-to-date. In order for the vulnerability to exploited, there needs to be malicious software on the computer that takes advantage of it. Ensuring the software on the computer is up-to-date and from trusted sources will help mitigate this as well as other security risks.
I’m holding-off, on buying a new computer, until I get, a TOTAL solution, and NOT just, “mitigation” — I assume, that THAT, is not here, yet .
In the meantime, on my Mac, I have turned-off the hyper-threading feature, thus incurring an up-to-40% performance hit, and I MAY be suffering from various application-bugs, that result, from that .