Dual CPU's vs. single?

[wafflepunk]

is there any logic to going for a dual Athlon MP system versus a single 2600+ or the like? other than running 6 instances of photoshop at one time, are you going to see any performance gains in gaming or such?

-waffle

[Cricket]

Originally posted by wafflepunk are you going to see any performance gains in gaming or such?

No..programs must be written to use both CPU's. The operating system must also be capable of using 2 (or more) CPU's. If not, only 1 CPU will be put to use and the other will just sit there doing nothing.

For home use, a single CPU system is more than adequate to do everything you need it to.

Cricket

[LiGhTBoY]

You don't actually need MPs to go dual, you can always close the bridges on 2 same speed XPs (not sure if they *need* to be same speed).
As for the performance , yes you will notice an improvement, because it will alow you to use 2 programs at once (folding on one cpu , gaming on the other ;-)) without any performance drop.

[HAL9000]

Not in a Windows based system. To allocate CPU resources like that, you pretty well need some flavour of 'nix. The OS and programs as Cricket said must support dual processing too. If you are considering duallies though, check it out, you can actually build a dually P4 Xeon system cheaper than a dually MP now.

[Cricket]

Originally posted by LiGhTBoY As for the performance , yes you will notice an improvement, because it will alow you to use 2 programs at once (folding on one cpu , gaming on the other ;-)) without any performance drop.

Only if the OS is dual or SMP capable and the programs or games are written to be used in a dual or SMP system (not too many games are...and not too many main stream programs are either, unless you're using a UNIX based system like HAL9000 mentioned).

If you have a dual processor PC and you use a OS that is not SMP or multiple processor capable, your dual processor computer will function like a normal single CPU computer (might actually be slower than a regular computer too).

Cricket

[Tuf]

Both of my CAD machines have dual processors. They are both really fast rendering large drawings. But Cricket is right that with some programs that are actually a little slower than if you just enable one processor. It is possible to have them both doing the exact same work at the same time which will slow things down.

With the fast processors that are available today I can't imagine why someone would want to build a duallie machine for normal use. It's actually a pain the butt to make it work right.

[Blakhart]

A dual sys with a smp os can do all the following at the same time:
Play a game, check email, play music, download anything you like, render a scene, and burn a cd.
Try all of that at the same time with any single cpu system.
The apps do not need to be multithreaded as the os has needs of its own. The os will attend os calls with one cpu while the other is handling app calls.
If you do all sorts of things at the same time, it is worth it.
If you do not load your system as much, the fastest single cpu sys with plenty of mem may be a better solution, especialy for games. There are no smp games that are stable, and they even run slower than on a single cpu sys. At least none that I know of.
As to the os, I have a feeling that a version of 'nix is better at smp than windows smp's. But windows smp will do. From what I see, windows loads a cpu completely before tapping the other, while nix loads both evenly. Dunno wich is really better, just a feeling.

[LiGhTBoY]

Originally posted by Blakhart A dual sys with a smp os can do all the following at the same time: Play a game, check email, play music, download anything you like, render a scene, and burn a cd. Try all of that at the same time with any single cpu system. The apps do not need to be multithreaded as the os has needs of its own. The os will attend os calls with one cpu while the other is handling app calls. If you do all sorts of things at the same time, it is worth it. If you do not load your system as much, the fastest single cpu sys with plenty of mem may be a better solution, especialy for games. There are no smp games that are stable, and they even run slower than on a single cpu sys. At least none that I know of. As to the os, I have a feeling that a version of 'nix is better at smp than windows smp's. But windows smp will do. From what I see, windows loads a cpu completely before tapping the other, while nix loads both evenly. Dunno wich is really better, just a feeling.

Blakhart is right here. Windows based on the 2k kernel do support duals but your progs do not need to support them. The program will just use the available CPU and when that is full , any more programs will use the second CPU. ;-)

If you are willing to spent a couple of days learning linux, then I highly recommend using that (you can play games on it 2, with Wine.).