Comment Re:PS3 (Score 2) 276
(Note: this is speculation, I never asked Nintendo about these, nor did I had any access to whatever internal documentation on RAM for the Wii - much less for WiiU)
Like I said, the 64M GDDR RAM of Wii is very quick, but optimized to be read and written in big chunks. It's not meant for per-byte random access.
I don't have the specifics at hand, but RAM is read in big chunks (32 bytes, 256 bytes, I really don't remember), and kept in cache from there. As long as you stay in that cache, it's all right.
Also, that RAM is used for GPU, DMA, and everything else external to the CPU. So its bandwidth is split between everything in the console. That means crappy bandwidth, split at controller side. That's GDDR RAM, tied down to the graphical chip, and that one has priority. That's why they added up so many features to transfer data back and forth from RAM. That way, you can do bulk transfers in background while the CPU is happily churning something else. Would it be that fast, there wouldn't be such tools.
On a side note, I'd take OP AC with a grain of salt. However, HDDs do transfer quickly when accessing data sequentially. So I don't say it's impossible to have the same CPU-side bandwidth. You are totally right about latency, that said; HDDs are very slow to seek.
Yet again, reminder this is for Wii, I have no idea how the WiiU works.