276
Why we don't have 128-bit CPUs
(www.xda-developers.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 23 Jun 2024
276 points (94.5% liked)
Technology
60112 readers
5074 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 2 years ago
MODERATORS
Is this a question?
We haven't even come close to exhausting 64-bit addresses yet. If you think the bit number makes things faster, it's technically the opposite.
It's a link to an article I found interesting. It basically details why we're still using 64-bit CPUs, just as you mentioned.
Comment OP must never learn anything new. Good find.
We don't even have true 64-bit addressing yet. x86-64 uses only 48 bits of a 64 bit address and 64-bit ARM can use anything between 40 and 52 depending on the specific configuration.
I think they were just adding to the conversation
I actually added detail that wasn't already discussed in the article?
I actually didn’t know that about addressing before your comment and so I found it very interesting, thanks
Some applications use those unused bits to add tags to pointers but it's important to mask those out before attempting to dereference the address. I'm not sure about ARM but x86-64 requires bits 49-63 to be copies of bit 48 (kinda like sign-extension), ironically to ensure that no one is using those bits to store extra data.
that was a nice chuckle.ty
Yeah, 64 bit handles almost all use cases we have. Sometimes we want double the precision (a double) or length (a long), but we can do that without being 128-bit. It's harder to do half. Sure, it'd be slightly faster for some things, but it's not significant.
And you can get 128-bit data to the CPU, so those things can be fast if we need them to be.
And we have wide instructions that can process this data, such as for multimedia applications.
Addressing and memory size has been the historic motivator for wider registers, but it’s probably not going to be in my lifetime that I see the need for 128.
There's plenty of instructions for processing integers and fp numbers from 8 bits to 512 bits with a single instruction and register. There's been a lot of work in packed math instructions for neural network inference.
For the people who don't know the answer? Yes.
Not everything you see is intended for your consumption. Let people enjoy learning things.
I totally agree. I know a teacher who who likes to say:
"I believe there really is no such thing as a dumb question. As long as it's an honest question (not rhetorical or sarcastic), then it's a genuine request for more information. So even if it's coming from a place of extreme ignorance, asking a question is an attempt to learn something, and the effort should be applauded."
Learned from the teacher. Thanks.
Woah, meta.
Yes, it is.
This is not a question, though.