Originally Posted by
quzar
In theory you could add as much as you want on any port, if you don't want it direct mapped. You could put 64mb direct mapped on the G2 port (modem/bba), up the 16mb main ram to 64mb (within the capabilities of the SH4 and fits in the memory map), the 8mb video ram to 16mb, and the 2mb audio memory to 4mb (although then you wouldn't be able to do the whole 64mb on the G2 port).
The limits on the polygon count do not have to do with the system ram, they have to do with the speed of the cpu and the connecting busses. The best things you could probably do to increase the poly-pushing abilities of the DC would to overclock the SH, then ensure that the ram is the lowest latency possible (many DCs used different brands of ram and the RAS/CAS timings fluctuated, so they were fixed by hardwired register).
There are two reasons nobody answered you. What you are asking for will never be done, and the fact that you have to ask means that you don't have the capability to do it. And, the way you wrote your posts also implies you wouldn't be able to contribute towards the creation of such a project.