resozv
The 2 main things to looks for in a computer that will affect WGT game play are RAM and CPU.
Dual Core machines almost entirely eliminate swing meter stutter, since most stutters are caused by another application on your machine making a demand on the processor when you are swinging. Therefore if the programs are written properly they will not tax the same "core". Also if an application is writing to your hard drive your meter will go crazy!! Therefore if you have the means the Intel® Pentium® D Processor with Dual Core Technology for the Dell GX620 should preform better.
The second thing is RAM - having 2 gig's or more is plenty and would work fine.
Lastly not computer related, but affects your game is your internet connection. I have never see great game play over a wireless network. it will stutter. Also if your internet connection speed is slow (regardless if you have cable or DSL or dialup) you will be constantly loading assets and it will affect your cpu and bandwidth which will affect your meter. you can go here to test your connection speed http://www.speedtest.net/ More often than not the actual speed you think you have is throttled down by your isp and can be very slow.