i have laptop
What is the make, model and SKU to your laptop?
Check to see if you have any BIOS updates pending on your laptop. Use DDU to remove all GPU drivers(intel, AMD and Nvidia) in Safe Mode, then manually reinstall the latest GPU driver sourced from Nvidia's support site,
here(but choose
notebook from the drop down menu), in an elevated command, i.e, Right click installer>Run as Administrator.
I checked my ram in cpu z , the first ram have cas 15,16,17,18 and the second ram have cas 21, 22, 23, 24
Are you mixing and matching two different sticks of ram?
On second thoughts, please pass on what you're seeing on CPU-Z courtesy of screenshots. Are you driving an external monitor with said laptop?