Optimizing Performance / PuzzlingFollow

Greetings Fellow Players,

Here is my setup

MSI 975X PowerUp Edition Mobo
550Watt PSU
P4 3.0ghz overclocked to 3.60ghz
2gb DDR2 Ram
Western Digital 250 GB HD 7200RPM
XFX GeForce 7600GT XXX Edition
Sound Blaster X-Fi Music

I keep my computer optimzed by defragging regularly, I keep my Swap File on a partition at the beginning of my second hard drive (also 7200rpm) and keep my computer spyware and anti-virus free. I also close all running apps before starting the game and usually have anywhere from 29-33 processes running when beginning to play.

I currently play everquest on the Balanced Preset. It plays so so, but it plays awful in any type of city including kelethin and even in greater faydark the performance is below par, generally below 30fps.

Now, I understand there is a big mega guide on how to optimize your settings and i've followed it several times but unfortunatly still either a) don't get a very good performance/visual quality balance or b) still have shoddy performance.

What I would like to see is being able to be in Kelethin at playable framerates but by also keeping a good visual quality. Any tips on what critical settings I should focus on that will make the biggest impact with the least amount of visual decrease?

I also have a G15 keyboard which shows my CPU usage, including the Hyperthreading. The graph is divided into two, each going to 50% representing the two "logical" cores. When playing EQ2, it only uses 50% w/sometimes going to 52-53%... WHen HT is off, it is using 100%, does this mean i get more processing power with EQ2 when HT is turned off? Thanks for any suggestions, input, and tips guys!