Do you guys get like if you overclock your gpu to 500 mhz or something any number really it would be maybe, and it works fine. But in gpu-z monitor or MSI Afterburner monitor it will say 501.4 or 468 Btw there are only examples, my point it is, do you get get it where the monitors show wrong frequencies by 1 mhz or even like 30mhz?
Its because the clock speed is actually based off of a system clock and while clock generators are fairly consistent they do have slight variation to them. If the base clock is supposed to be 100MHz but yours is actually like 100.3MHz then setting something based off of it to 500MHz will result in a frequency of 501.5 MHz. Very few systems are actually at perfect base clock speed many are a tiny bit off but its consistent and doesnt change so it still works fine.
Typically there is a quartz crystal that determines the base block and for some it is a very last resort for overclocking. The frequency for it is low but it is multiplied before system clocks are determined then from there cpu and ram. Gpus and sometimes other devices use this. If the crystal was slow then if the device is under warranty then just RMA but if not replace it.