Single core vs Dual or Quad Core help?

[HTML_MAN]

Hey Guys,

My mates and I where wondering what actually makes a Dual core or a Quad core better than just a single core?

Couldn't they fit more transistors on just one big core? And if you have say quad cores wouldn't the ratio to power to size be the same?

Like if you cut a pizza into 4 it isn't any different.

Sounds stupid, maybe not but its just bothered us for a long time.

[jlreich]

Couldn't they fit more transistors on just one big core?
Sure. And that's what they did for many years to make CPU's better by giving them more and more capabilities. With more transistors they put more multimedia extensions in, larger and better brand prediction, more registers, etc. That and crank up the clock speeds faster and faster. Then they hit a brick wall with clock speeds and they decided that multiple cores was the way of the future.

Like if you cut a pizza into 4 it isn't any different.
If you have one big slice only one person can eat from it at once. Maybe it is enough to feed all four people but only one can eat at a time. You have to take a bite and pass it to the next guy, he takes his bite and passes it on.... If you have four smaller slices four people can eat at the same time eating from their own slice. ;)

All a single core CPU can really do at one time is one single thing. Even though it may seem like it is doing many different things at once it is not. It just fools you by switching back and forth from one application to another very very fast. Even with Hyper Threading this is still true.

When you have multiple cores the CPU can truly do more than one thing at a time. For obvious reasons this is highly beneficial when multitasking. Not so much for a single unoptimized application. This is why if all you do is surf the web and do email anything more than a dual core is a waste. But if you are running an application that is optimized to work with multiple cores, meaning it can send one part of the code to one core and another part to another core and so on, then it can run that single application much faster. Most modern games are made to use multiple cores efficiently, and applications like Adobe Photoshop and Premier are optimized for as many as 26 cores.

If all you ran where old applications then a faster clocked single core CPU would beat out a slower clocked multi core chip. But if you are like many people today you have several thin gs going on at once. Music, you tube, email, IM, maybe burning a DVD etc.

Ever tried running the latest game while burning a DVD in the background on an single core CPU? It doesn't work very well. ;) I do it all the time without a single hitch with my quad and even with my old dual core it wasn't an issue.

There is definitely more to it than this, but you really don't want to go down that rabbit hole. :p

[mjc]

There is also the fact, that they were able to downsize the physical size of the CPU itself that more than one could be fit in roughly the same area as a single core, a few years back, could.