It must be the graphic card. If not it is a graphic card with Directx 11 hardware the emulation it's choppy and with bugs. I think that it is like that. The problem it is not in the processor. But the Dreamcast has the same hardware and in NullDC the games run well. But if you want upgrade for a new graphic card, maybe your motherboard is not compatible with the newest cards. In that case you need a new system or a motherboard compatible like a X48.
