Why won't FFXI run smooth on my computer? (Specs listed)

[{Pug}]

Hi.

My specs:
1.1 Ghz AMD Athlon
512MB SD RAM
Geforce 4 Ti4200 128MB DDR (@4x)
128 MB AGP Aperture Size
1024x768 Resolution w/ 1024x1024 Textures
High Texture Compression
AA Off
Benchmark Score: 3,200 (MX Score: 2,700)

I used to run an MX 420 64MB, and there is little improvement when I installed the Ti4200. It doesn't seem to matter what resoluton I run either. One annoying thing I've noticed is every couple minutes my game freezes up for a brief second. In outdoor environments I get near 60 FPS, but in areas like the Highlands (sandstorms) and Dangruf Wadi its more around 20 FPS. Then I get into Bastok, and it dips down around 10-15 FPS. My friend has the exact same specs except for his RAM is DDR and it runs @ 60FPS constant everywhere. Could it be my hard drive is shot? It used to defrag in a few hours, and now takes 4-5 days to complete. Do I really need DDR RAM that bad? I hope someone can help, thanks.

[Mithrankittycat]

SD RAM <- Ghetto
CPU under P4 1.6 GHz or athlon 1600+ <- Ghetto
The game is capped at 30 FPS.

Resolution is too high for that old of a system.
Disable bumpmapping and plant animation and weather effects.