New
#180
Not exactly. Spectre OS switches seem to be just OS memory management changes (just did a bit more reading and made an inference).
BIOS updates are better because they don't rely upon software patches to deliver them (both the Linux and the Windows methodologies are weaker in this regard) wipe the OS and you wipe your protection, until you reenable it in your new OS. On the flipside, OS hooks will catch (and cause a performance penalty) unless you disable them.
If Speculative Execution was disabled, you get the performance penalty all the time. Modern CPU architecture derives it's performance by Speculative Execution during otherwise idle CPU cycles. You can have fast OR secure.
It's an architectural design flaw / premise that reaches as far back as the Pentium Pro of 1998. Speculative Execution has been a thing in other CPU architectures since the 1960s which is pretty much the nascent computer.
Chromebook patches the same way; BIOS/Firmware update or because it's based on Linux, updates to ChromeOS enable Site Isolation and KPTI.
Meltdown/Spectre vulnerability status for Chrome OS devices - The Chromium Projects