I ran it with the latest Intel microcode files and got this message in Event Viewer:Interesting, I didn't know you could basically force Windows to side-load CPU microcode updates. I plan to try this tonight and see if the results from Get-SpeculationControlSettings change at all, that is assuming there are any microcode updates for Westmere-EP in the first place!
An update for this CPU was not found. No update has been attempted.
So basically there is no chance of any new microcode updates for X58 CPUs even for this serious flaw, considering there haven't been any since at least 2012.