i just got another naomi 2 with the cart vstriker3... and i'm getting big slowdowns when a lot of players are on the screen... mobo ram test went all ok, same for rom board test... is this a 'normal' issue with this game?
The more 3d action there is on the screen, the more power is required to render them. Have you tried making adjustments to the PSU? Try increasing it slightly to see if the slowdown clears.
VF4 just has 2 characters on the screen at a time. Soccer has 10-20 people at a time. VF4 has nice backgrounds, but the are static and easy to render. It's the moving characters that take up alot of CPU time.