Lol. My comp is even worse and it still manages to run GWX. Of course it freezes every time I switch screens or try to look around, but I got used to it. I just stick with my map view, scope/UZO... what else... crew management and TDC, and thats enough. You really don't have to climb to tower to enjoy the landscape often to be deadly accurate as a Kaleun.
PS But it starts lagging very, very badly, when too many targets around, especially when approaching convoys and when close to ports. That can really drive one mad...