A contemporary x86, RISC, mixed (ISA + accelerators), or what other CPU? I think CPU is a broad term. :) Anyway, Wikipedia has a detailed write-up that assembly experts can base a comparison on:<p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;PDP-11_architecture" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;PDP-11_architecture</a><p>It wasn&#x27;t that PDP-11 made C implementations more efficient. It&#x27;s that C was a BCPL specifically designed to compile easily and run fast on their PDP-11. That&#x27;s why I can&#x27;t overemphasize C&#x27;s actual history vs the lore that people repeat. It&#x27;s literally an ALGOL language with every feature that couldn&#x27;t compile on 60&#x27;s and 70&#x27;s era hardware chopped off with some extensions added latter.<p><a href="http:&#x2F;&#x2F;pastebin.com&#x2F;UAQaWuWG" rel="nofollow">http:&#x2F;&#x2F;pastebin.com&#x2F;UAQaWuWG</a><p>Worked fine for a PDP-11. Yet, forcing its memory model or tradeoffs into a language used on different hardware can cause unnecessary problems. In contrast, Hansen&#x27;s Edison language deployed on PDP-11 had only five statements (extreme simplicity haha) but would map efficiently to most architectures. As would Pascal and Modula-2 that inspired it &amp; were safer.<p><a href="http:&#x2F;&#x2F;brinch-hansen.net&#x2F;papers&#x2F;1981b.pdf" rel="nofollow">http:&#x2F;&#x2F;brinch-hansen.net&#x2F;papers&#x2F;1981b.pdf</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Modula-2" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Modula-2</a>