I'm playing through HL2 again on hard and getting 7-8 fps on the coastal level. I'm at the point where I've cleared the barn and house of combine, and chucked a few cars off the road to get past, before reaching the big roadblock before the combine forcefield. This is where there is a combine soldier on top of a petrol advertising hoarding.
I have AA/AF disabled, although I never had these problems before with the same card (see sig).
Can anyone suggest anything?