Stock clocks? HT enabled or disabled? IIRC the first game performed worse with HT enabled by a non-insignificant amount. Maybe something to test, but I doubt that's the cause of your issue. You should be getting significantly better performance with that setup.
Stock clocks, yeah. I've never given HT a single thought, so I assume it's enabled by default, which would mean it's enabled now too. FWIW, I played the first game a while ago and it performed absolutely beautifully with the highest settings.