Thoughts about the new VRAM configuration for the PSP

[PC-Engine]

MIPS16...

 

[Panajev2001a]

with this thread, this is the first time I have heard any info whatsoever on Graphics Synthesizer 2, other than the much publicized plans of Sony back in 1999 to produce an GS2 by 2002

also, is GS 1.5 the same thing as GS I-32 ?
(GS I-32 is the 32 MB eDRAM version of GS used in GSCube)

No, IIRC it used different e-DRAM.

I myself never really thought about PSP using some derivative of the work put into GS2.....


and so PSP really has only a 332 Mpixel *textured* fillrate. well, I suppose Gamecube advocates can breath a sigh of relief. they now can know that PSP GPU does not slightly surpass Flipper in textured fillrate, unlike before when it seemed that PSP was slightly ahead of Gamecube's Flipper in that area (PSP's 664 vs Flipper's 648 Mpixels)

I think the rendering core is not a brand new design, but it picked up where the rendering core of GS 1.5-2 left off.

PSP would still beat GCN in Textured Fill-rate as you forgot to scale by screen resolution.

Still, GCN's Flipper has the ability of doing early-Z checks to reject some occluded pixels and I hope that the PSP has some fill-rate saving features or else we have way too much combined T&L power (GPU's T&L unit + the VFPU) compared to the Shading power and Fill-rate of the GPU.

 

[Panajev2001a]

*Shakes fist* I see no bandwidth to load the textures in the cache

Why would you have to though? Majority of GPUs out there don't have the raw bandwith available from their VRam to support maximum rendering load.
They rely on caches to minimize bandwith use and thus allow them to maintain the speed.

I do not think the PSP's GPU is like all GPUs, I think I know where SCE took some of their ideas from.

Relying on caches to get single-cycle bi-linear for each of the 4 pipes is fine.

Using 512 bits e-DRAM and not being able to feed 4 pipes with single cycle bi-linear is something I am not too happy with.

I am sure developers shouted with joy when they discovered bi-linear fill-rate was 332 MPixel/s and tri-linear was what... 166 MPixels/s ?