CPU/Processor error rate in calculations
Some things are present. cpuid with eax=01H return MCA–Machine Check Architecture in EDX 14-bit:

Machine Check Architecture. The Machine Check Architecture, which
provides a compatible mechanism for error reporting in P6 family,
Pentium 4, Intel Xeon processors, and future processors, is
supported. The MCG_CAP MSR contains feature bits describing how
many banks of error reporting MSRs are supported.


Check Intel reference volume 3B chapter 15 MACHINE-CHECK ARCHITECTURE:

The Pentium 4, Intel Xeon, Intel Atom, and P6 family processors
implement a machine-check architecture that provides a mechanism
for detecting and reporting hardware (machine) errors, such as:
system bus errors, ECC errors, parity errors, cache errors, and
TLB errors.


Intel 64 CPUs have additional checks, see chapter 15.6, for example there are:


Parity error in internal microcode ROM
FRC (functional redundancy check) master/slave error
Internal parity error.


See also:


https://stackoverflow.com/questions/2580933/cosmic-rays-what-is-the-probability-they-will-affect-a-program
https://softwareengineering.stackexchange.com/questions/34120/how-often-do-cpus-make-calculation-errors