Hacker News new | ask | show | jobs
by userbinator 3342 days ago
there was a brief window in the eighties

This was also the very brief time when memory was actually faster than the core, making it possible to contemplate things like large fixed-with instruction encodings, since the main bottleneck with the early CISCs was instruction decoding and not fetch bandwidth; it is unlikely that, had this period not existed, RISC would have developed in the way that it had.

1 comments

It's ironic that Ditzel went from Berkeley RISC to Bell Labs and helped develop CRISP [1]. This was the invention of the Decoded Instruction Cache which solved the fetch/decode bandwidth problem. You could have a CISC and not have to worry about decode bandwidth. You could have a wide μop and not have to worry about fetch bandwidth.

[1] http://mprc.pku.edu.cn/~liuxianhua/chn/corpus/Notes/articles...