Tanenbaum and Torvalds [was Generalizing address-space isolation] [LWN.net]

Tanenbaum and Torvalds [was Generalizing address-space isolation]

Posted Nov 10, 2019 16:51 UTC (Sun) by jezuch (subscriber, #52988)
In reply to: Tanenbaum and Torvalds [was Generalizing address-space isolation] by kreijack
Parent article: Generalizing address-space isolation

BTW, I have recently learned that human (natural) languages have a deep parallel to the CISC/RISC split. Some have simple syllabes that can be pronounced quickly, others have complex syllabes that take more time to articulate. But the end result is that when you measure information content over time, all languages have basically the same throughput of around 40 bps. So perhaps this is also what happened with RISC: yes, you could execute instructions faster, but this was completely offset by the fact that you needed more of them to do the same thing.

I wonder if the languages with complex syllables are also just fronts for a language with much simpler syllabes underneath, though ;)

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Tanenbaum and Torvalds [was Generalizing address-space isolation]

Posted Nov 11, 2019 18:17 UTC (Mon) by rgmoore (✭ supporter ✭, #75) [Link]

My impression is that a big part of what happened was that the RISC vs CISC battle took place when raw computing power was the main limit on how fast a computer could accomplish things, so there was a serious issue of whether it was better to have many small operations with high clock speed or fewer bigger operations with a slower clock speed. But what's happened since then is that processors have outstripped the rest of the system to the point that instruction set complexity is no longer where the action is. Instead, the limit on the computer is how fast and efficiently you can get instructions and data to it. That means the big battle is now things like how big your cache is and how cleverly you use it, how you can minimize RAM latency, and whether you can avoid backtracking in a deep pipeline by using speculative execution.