341
Linus Torvalds says RISC-V will make the same mistakes as Arm and x86
(www.tomshardware.com)
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 12 Jul 2024
341 points (92.7% liked)
Technology
59148 readers
1932 users here now
This is a most excellent place for technology news and articles.
Our Rules
- Follow the lemmy.world rules.
- Only tech related content.
- Be excellent to each another!
- Mod approved content bots can post up to 10 articles per day.
- Threads asking for personal tech support may be deleted.
- Politics threads may be removed.
- No memes allowed as posts, OK to post as comments.
- Only approved bots from the list below, to ask if your bot can be added please contact us.
- Check for duplicates before posting, duplicates may be removed
Approved Bots
founded 1 year ago
MODERATORS
Anyone willing to summarize those mistakes here, for those who can't watch the video rn?
He doesn't list what the mistakes will be. He said that he fears that because hardware people aren't software people, that they will make the same mistakes that x86 made, which were then made by Arm later.
He did mention that fixing those mistakes was faster for Arm than x86, so that brings hope that fixing the mistakes on Risc V will take less time
I think it was something with instruction sets? Pretty sure i read something about this months ago.
No, it was about the prediction engines that contain security vulnerabilities. Problem is that software has no control over that, because hardware does future predictions for performance optimization.
Aah, right, that.
Prediction is a hard problem when coupled with caches. It relatively easy to say that no speculative instruction has any effect until it's confirmed taken if you ignore caches. However caches need to fetch information from memory to allow an instruction to evaluate, and rewinding a cache to it's previous state on a mispredict is almost impossible. Especially when you consider that the amount of time you're executing non-speculative code on a modern processor is very low.
Not having predictions is consigning yourself to 1990s performance, with faster clocks.
I mean, that's all chip architectures are, so yes.