Re:Raspberry Pi RP2350 Now Available for Purchase, Stacked M...
by dgacmu on Wednesday March 19, 2025 @09:34AM
(#43411774)
cost and power and latency.
The rp2040 is fabbed at 40nm. It's _really_ expensive to fab on things closer to the cutting edge, and the volume of rp2040/2350 sales simply isn't enough to justify it. (Also, it's harder to design and ends up binding you more tightly to a fab). At 40nm, adding 1MB of SRAM would literally make the chip more than 2x larger, which would increase the cost by quite a bit -- and probably make the SRAM slower. You can see a die shot / layout here:
Notice how much of the area is already SRAM. That's hefty. It would make the chip more expensive without much of a corresponding return on applications enabled. People who need more SRAM can add an external SRAM if they need it.
The rp2040 is fabbed at 40nm. It's _really_ expensive to fab on things closer to the cutting edge, and the volume of rp2040/2350 sales simply isn't enough to justify it. (Also, it's harder to design and ends up binding you more tightly to a fab). At 40nm, adding 1MB of SRAM would literally make the chip more than 2x larger, which would increase the cost by quite a bit -- and probably make the SRAM slower. You can see a die shot / layout here:
https://www.raspberrypi.com/products/rp2040/
Notice how much of the area is already SRAM. That's hefty. It would make the chip more expensive without much of a corresponding return on applications enabled. People who need more SRAM can add an external SRAM if they need it.