Nod, more than enough considering its speed.
Gamecube stream its textures and geometry on the fly and its automatic, what i mean is, its not like ps2 where developers have to tell its memory controller what to get or not from the dvd. The problem with PC, even with huge ammount of rams is that developers will never take use of the technology till 2 years, there is no way to make a game that can stream on the fly with low latency, simple because PC is an open platform.
16MB sdram = Sound, animation and caching
24MB 1t-sram = Textures, geometry and AI
3MB embedded 1t-sram = 1MB for texture stream, 2MB for zbuffer/frame buffer.
Its very well done, dont be surprised to see 1t-sram based video cards in a few years on PC (radeon3?) considering it
BARELY cost more than DDR. In fact, i bet 50$ you'll see 1t-sram in the next generation console, its THAT advanced.
DDR will simply never catch up to 1t-sram's latency, you would need the memory speed to be over 5ghz almost
And like you said, s3tc, vertex compression (which is higher than 2:1) plus virtual texturing will take care of space, the streaming is just ice on the cake
and no, ps2's streaming capabilities doesnt come close to gamecube, mainly cause it lack compression, unless you call the shittiest compression algorythm on earth, jpg, to be good
I've also heard flipper can be hacked into a deferred renderer, which unless you didnt know, its the most effective HSR you can imagine. They just store the display list on the gekko's L2 cache (its small, no worries) then the simd unit calculate, send to flipper's embedded memory and voila, deferred rendering
Most developers will just go with the traditional rendering though.
To put it simple, 1t-sram = perfection