Your system will run GWX at full settings (AA & AF + High Res) with no problems at all.
Where are you getting 'hiccups'?
The trick with SH3/GWX is that you have to let the graphics load. So when starting in port, do a 360 deg rotation while in port this will be stuttery but once they are loaded the game will be fine. This goes for all gfx in SH3/GWX, they need loading into the memory.
If you need more info, just ask.
Enjoy the GWX ride
