Someone else has addressed your other points, but for ECC: This will not detect an error in computation, only a bit flip in data. The current way to mitigate c

Someone else has addressed your other points, but for ECC: This will not detect an error in computation, only a bit flip in data. The current way to mitigate computation errors is to have two processors to detect an error in computation, or more to do a voting system if mere detection is not good enough. Since you cannot detect a computation error with a single CPU (without overhead somewhere, and thus lower performance), you can’t slow down to fix it. The ECC systems I have worked with can fix a 1 bit error and detect two or more bit errors. They do this by using an algorithm to convert the original data in to an output that is bigger than the original (e.g. 64 bytes is now 72 bytes). This output data does not make sense until passed through the reversing algorithm. So basically the overhead is zero since the memory controller is running the algorithm in hardware every time anyway, so no slow down.