Upgrading won't get rid of stuttering. I have a fairly high spec. machine (GTX 980, i7 4790, 16GB RAM) and still have the issue. There are various theories regarding the stuttering like inefficient code, laggy network, hardware but no one seems to have pinpointed the cause as yet. You should always use a wired internet connection since wireless can experience dropouts. Also check your internet connection is good. Not all ISPs are the same.
Back to your question about memory and GPU usage, can you provide more details about your current setup?
1. Memory in GB and type (i.e. DDR3...)
2. GPU type, make, memory and memory type
3. Hard drive type e.g SATA, SSD
4. Processor make and type and clock speed
Also have you compared your spec. against FD's minimum spec?