I tried Apple Diagnostic tests today out of curiosity for the first time and got an Error PPM003 related to faulty memory module. I never experienced any crash or panic. Boot time is 7 seconds and system is really smooth. I have 32GB installed of RAM but I am not sure which one is faulty. How can I find out which one ? I guess it's a dual channel so not possible to test them one by one. Any hint please ?