4 ms·
> 256 MB was dedicated to graphics and only had REDACTED Mb/s access from the CPU I wonder what the REDACTED piece means here, aren't the PS3 hardware specific
by accrual 2y ago
> 256 MB was dedicated to graphics and only had REDACTED Mb/s access from the CPU
I wonder what the REDACTED piece means here, aren't the PS3 hardware specifications pretty open? Per Copetti, the RSX memory had a theoretical bandwidth of 20.8 GB/s, though that doesn't indicate how fast the CPU can access it.
- monocasa 2y agoI don't know why it's redacted here; maybe he couldn't find a public source. It is a mind bendingly tiny 16MB/s bandwidth to perform CPU reads from RSX memory.
- OptionOfT 2y agoJust to make sure, I read that the CPU reads from the RSX at 16 megabytes / sec?
- maximilianburke 2y agoI can't recall exactly but that sounds right. It was exceptionally slow.
- MBCook 2y agoThat’s why getting DMA right mattered so much.
- maximilianburke 2y agoI'm not quite sure what this means? DMA is the only mechanism that the SPUs had to access memory outside of their local store; it wasn't a matter of getting it right or wrong. Reading RSX memory by SPU DMA wasn't any faster than reading it from the PPU.
- MBCook 2y agoI’m sorry I thought you meant the CPU not the GPU. I didn’t realize DMA didn’t help with GPU memory.