In the CPU options make sure you enable any speed hacks available.
If you're trying a 3d game (or any game with 3d elements), you have no chance running it smoothly with only a dual core.
Dual core is best. PCSX2 doesn't have quad-core support.
I'm running it smoothly without crashes on the 1474 beta. Not sure about Dust of Osiris, but I think that's also 60 FPS.
I have an AMD Phenom 9150e Quad-Core at 1.80 GHz with 6Gb of RAM.
Default Cycle Rate and no VU Cycle Stealing. All other speed hacks are on. Using the other speed hacks caused me to crash at char. select screen.
GSDx 1650: Direct3D10 Hardware at native resolution. Interlacing is Weave tff. No scanlines or anything.
I probably don't have to say this, but remember to enable dual core support in Config->CPU.