Last visit was: It is currently Mon Dec 10, 2018 12:24 am


All times are UTC-05:00




Post new topic  Reply to topic  [ 2 posts ] 
Author Message
 Post subject: RISC vs CISC Architecture
PostPosted: Wed Aug 10, 2011 3:17 pm 
User avatar
 

Joined: Sun Feb 12, 2006 8:56 pm
Posts: 1019
Website: http://eddieringle.com
Location: Detroit, MI
I've heard from both sides on the matter, but I'd like to see all the arguments in one centralized place (here).

Here's what I've heard:
  • CISC fans say that their architecture can do in one instruction what a RISC machine must do in many
  • RISC fans say the "super instructions" CISC is composed of slows down the processor as a whole, and RISC CPUs are generally cheaper than CISC CPUs

_________________
-- Eddie Ringle

Check out Elysian Shadows and consider backing us on Kickstarter!

====================================

Image


Top
Offline   
 Post subject: Re: RISC vs CISC Architecture
PostPosted: Wed Aug 10, 2011 11:46 pm 
User avatar
 

Joined: Sat Jun 03, 2006 3:51 am
Posts: 1186
Website: http://griffinhart.livejournal.com/
Yahoo Messenger: Squall591
AOL: FinalWarrior591
Location: Look at my horse, my horse is amazing!
Linked this thread to one of my roommates; here's the chatlog.

Me: Interesting question, outside the scope of my knowledge.
Him: Yes?
M: Your thoughts?
H: If you build a button for every possible thing your machine can do, you have a freaking lot of buttons vs. having comboes of buttons for doing things.
H: Freaking lots of buttons means you can just look for the button you want.
H: Second one needs a manual to find out which combo for what, since it's inobvious.
H: In the end, same result, it depends on the scope of your project, as you can see, the tradeoff is mainly in how expandable stuff is.
H: Either way, doing anything complicated is going to require lotsa buttons.
H: If you try to make a button for every possible action, this is obviously unfeasible, yeah? So you'll start to build on top of existing buttons.
H: So everything converges to that point at the high level.
H: aka, this argument is stupid.
H: Really, once you're actually doing high level work, you're writing programs, right?
H: And programs are sequences or combinations of instructions, therefore, you're doing at a high level what RISC processors do at a low level.
H: What it comes down to is at where it's acceptable.
H: Sometimes if you code a function into hardware it can be done faster, and it's worth it.
H: Sometimes, the function is so obscure that why bother? Just do it as a compilation of instructions.
H: So, if you're running like, machinery that has very few possible stuff it'll ever need, it might be feasible to have good coverage in hardware.
H: But this also means your hardware is very specialized for that machinery --- not generally usable for things outside of it.
H: Is this level of performance required? Well, that's of course up to the designer to decide, yes?
H: That's really what it boils down to.
H: Super simplistic view, but I think it covers the main issue.
H: Besides, from a "let's step back and look" view, the two systems aren't completely opposites.
H: you can have a basic instruction set for building programs from and then having specialized hardware for specific tasks if they're particularly important. Gee, I wonder what that sounds like?
M: Iono, a computer? :v
H: Indeed.
H: Which is why this argument is silly.

(I was planning on posting up through "aka", but then he said more stuff that I thought would be relevant/edifying.)

-- Griffinhart

_________________
"My word is my honor. My honor is my life."
-- Demonchild, Angelkin, the Blackest Seraph, the Final Warrior

Image


Top
Offline   
Display posts from previous:  Sort by  
Post new topic  Reply to topic

All times are UTC-05:00


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Theme created by Miah with assistance from hyprnova