[simbeb]

Hi

I have a desktop PC which I'd like to replace with a laptop. Because I do mainly video processing I don't want less than the 2Ghz of CPU I have on my current PC. There are lots of dual core laptops around on the market. So my question is: does a 1.66 or 1.86Ghz dual core processor have more processing power than a single 2GHz?

Cheers.

[Dave Hybrid]

http://en.wikipedia.org/wiki/Multi-core_(computing)

[mrdaveyk]

hhmm that link doesnt work dave

http://en.wikipedia.org/wiki/Dual_core

i think though, in general yes, but its a touchy subject with alot of but's

[Dave Hybrid]

Originally Posted by mrdaveyk i think though, in general yes, but its a touchy subject with alot of but's

Thanks and yeah, that's why I posted the link.

It isn't as simple as two cores = twice the power.

There is more to take into consideration but in general two cores are more efficient than one.

[Carbon]

Yeah, you can't double the clock speed but they're more efficient. Even in non-multithreaded apps, Windows can dump itself on one core and the app on the other. Don't mind the clock speed difference.

[link590o]

since the answers seem split up, i'll combine it.

dual core processing: it means you are splitting the work you're doing onto more than one processor. and since the load is split, it becomes easier to process.

and as the article states, since there are two and two processors emit a stronger signal than just one, more data can be transferred at once.

combine those two ideas and you have a very fast way to sort through data.

some processors can work faster than others. hence the gigahertz speed. so now you can sort of see that 2 cores doesn't mean 2x the speed. the factors above are really where the changes take place.

that's the simple explanation. or as simple as it gets. i took a look at that wiki article they showed you and it's very very wordy and heavy on terminology the average user isn't going to bother figuring out.

hope that clears things up a bit more.

[Grongle]

Let me attempt a very far-out analogy.

You have a yard full of leaves that you want raked up.

You send out your son to rake them.
— OR, you send out BOTH your sons to rake them.

So—will your two sons rake them up twice as fast? Maybe. Maybe even more than twice as fast.

Or, for a dozen different reasons, maybe not.

However, in theory at least, dual cores are much better; and quad cores are better than that. They are good enough that they are not merely trendy, and you can take them seriously if you are buying a new system. But, like the kids raking the leaves, they might not give you 2x or 4x the performance, either, and it would be very risky to presume they would.

Beyond that, as Carbon and Link suggest, you get into the guts of the thing, and you have to study all sorts of specific variables—in a world a long way from leaves on a lawn.

[philthomas]

What if he only has daughters ?

[spot]

I'd be cautious, simbeb. Go and read whether your video software's deliberately and ecstatically multi-threaded or not. It ought to be but if it isn't then you really do need the clock speed. Hiving off the Operating System background tasks to the second processor is great in theory but that background stuff might only be taking up 100MHz worth of your clock ticks, if that. Probably a lot less unless you're actually doing something as a second task. If your main processor load - the video package - isn't explicitly going to hog both processors then you'll be running very inefficiently.

[Grongle]

@Simbeb, when you've chosen your new system, it would be very interesting to hear what you chose and why.