CPUID is a CPU instruction that returns 60+ fields about the processor: brand string, family, model, stepping, supported feature flags, cache topology. Anti-cheats read all of it and aggregate into a fingerprint.
Some fields are stable (brand string, family) — every CPU of the same model has the same value. Others are unique (Processor Serial Number on older Pentium III, AMD PSN). Modern CPUs no longer expose the unique serial — Intel removed it back in Pentium 4.
What stayed unique: TSC (Time Stamp Counter) calibrated against the real-time clock, plus PMU (Performance Monitoring Unit) calibration data. By aggregating these into a hash, anti-cheats get a quasi-unique CPU signature.
An HWID change on the CPU side requires intercepting CPUID at user level and feeding back consistent fake values. Risky — it can break drivers and games that rely on real CPU info. Our changer leaves CPUID alone and works only at higher layers.
Bottom line: 90% of anti-cheats don't reach CPUID; for the rest the only physical solution is replacing the CPU. We don't recommend software CPUID spoofing for safety reasons.