Ram
Ram
Your current setup has 4GB of 2400MHz RAM, and you're considering adding more. The technician warns against combining 4GB with 8GB, suggesting it might lead to stability issues. Are you sure about the upgrade plan?
Make sure you have more than 8GB of RAM; otherwise, performance drops significantly to single-channel speeds for the rest of the 4GB.
It shouldn't be a problem, though it isn't perfect since only one memory channel gets the full amount of RAM. You'll get quick data speeds until you reach the 8GB mark, then performance drops to single-channel speed.