Hello. I own an ASUS ROG G551-VW laptop. I noticed that when i install, copy or extract the contents of an archive, my laptop slows down to the point i can't even switch tabs on Chrome without waiting 10-15 seconds, and the hard drive activity light is constant on. Firstly, i wanted to buy another HDD, a 2TB SSHD. But after i ran UserBenchmark, it said my RAM speed was below average. So the RAM could be the cause of the slow down? And if it is, would there be a problem if i buy a 4gb module and keep the 8gb module that i have now?