PS3 chip diagrams (CPU+GPU) from 2002-2004 - Patents by Masakazu Suzuoki - SCEI
This was the original CELL-based chipset (2 separate dies) for PS3:
"Broadband Engine" (CPU) and "Visualizer" (GPU)
You'll notice the Broadband Engine CPU chip had 4 Processor Elements. The finished Cell for PS3 had just 1 beefier Processor Element.
Each Processor Element had a PowerPC-based "PU" which later became the PPE, as well as 8 APUs which later became the SPEs.
The "Visualizer" GPU contained 4 cut-down Processor/Visualizer Elements, each with a smaller/weaker PowerPC-based "PU" / PPE, plus 4 APUs / SPEs. In addition, within each Processor/Visualizer Element, there was a
Pixel Engine, most likely containing multiple pixel/raster pipelines (in modern GPUs these are the ROPs), as well as an Image Cache (embedded VRAM/DRAM of some sort) as well as a CRTC (Cathode Ray Tube Controller).
The entire 2-chip CELL-based Broadband Engine CPU and CELL-based Visualizer GPU made use of 64 MB of embedded DRAM to massively speed-up communications within the CPU and GPU (and perhaps between the 2 chips as well?). This of course would've massively reduced the burden of the main external RAM (Rambus Yellowstone aka XDR) it would've had, be it 256 or 512 MB.
All the patents and diagrams related to the CELL CPU and CELL GPU by SCEI's Masakazu Suzuoki can be found here:
There was also a massive thread on all of this, on Beyond3D, here:
Obviously the Visualizer GPU was scrapped. SCEI went to Nvidia. Together they developed the RSX / Reality Synthesizer GPU. It was based on Nvidia's NV47 / G70 / G71 GPU, used in the GeForce 7800 series. As many know the RSX for PS3 was a custom, cut-down version of NV47 / G70 / G71 / GeForce 7800. The PS3 version had half the pixel pipelines / ROPs (8 instead of the full 16) as well as half the memory bus width (128-Bit instead of 256-Bit.
I often wondered what the PS3 based on the full 2002-2004 2-chip CELL-based (CPU + GPU) chipset would've been capable of compared to the final PS3 that was released in 2006.
Well, there's no doubt that the soon-to-arrive PS4 will be superior to even the most powerful PS3 concept :cool: