When I still owned my C65 I made a YouTube video of it running Stunt Car Racer to show how much faster the C65 is than a stock C64. You can see it below:
Since the C65GS is now able to run some software, I thought I would try Stunt Car Racer out on it.
In the still image below we can see that it is working fairly well. The vertical graphics glitches are a known problem with bitmap mode on the C65GS, and I will fix them in due course.
But the real question was how fast it would run. I knew it ought to run quite fast, and that it lacks any vertical blank interlock, so it would run as fast as it possibly could.
Here is a few seconds of Stunt Car Racer running at Ludicrous Speed. It goes without saying that it was entirely unplayable at this speed.
It looks like the CPU redesign I am doing should end up at 48MHz and somewhere between 30x and 50x C64 speed. I'll have to post an update when I get to that point.