The Brutal Performance Impact From Mitigating The LVI Vulnerability

John The Ripper is another workload where the increased LFENCE usage can lead it to less than 10% the original performance.

GraphicsMagick as an imaging program was also dramatically hit from the GAS options. Thankfully with the information public at this stage regarding LVI, users shouldn't need to be rebuilding programs like GraphicsMagick with these assembler flags -- assuming no further attacks are exposed that would warrant widespread use of these options on affected CPUs.

Video encoding performance is also killed should there end up being the guidance to build more common software with these new assembler switches beyond any very security-minded or SGX-using software.