Can't intel and amd just change how long a core stays at a turbo frequency to mitigate this? I.e.: if it scales up by 1hz, it can't scale down by that much until N number of cycles.
This would add noise to the measurements which should cause an exploit to take longer but it wouldn't prevent the exploit.
Pardon my ignorance but why wouldn't sufficient noise make it practically impossible to timing attacks. Very short secret material being processed multiple times?