Can 2 processors be grouped together to act as 1?

[ShawnD1]

This is just a theoretical question.

Some of you may remember the video cards that had 2 processors on them (Volari Duo, ATI Rage Fury Maxx, Voodoo 5500, Voodoo 6000) and how that setup actually worked.

Tech people are always saying that having dual CPUs doesn't help gaming performance because the game is just 1 executed file so it just sticks to 1 of the processors (which makes sense). Dual processor video cards seemed to operate as 1 piece so having 2 processors really did yield almost double the speed. Can that be done with central processors as well?

[ArcticFox]

If I understand you correctly, you want two 2Ghz procs to act as a single 4Ghz right?

While technically/theoretically possible, I wouldn't do it. FSB speed anyone? You'd have to have a massive, massive pipe between the procs in order for it to work, about 4Ghz in fact. With just 800Mhz or so, you might as well fuggedaboutit.

[ShawnD1]

Well that sucks.

How did those dual processors video cards work then?

[beppodmime]

Well, kinda sorta like having two physical, identical processors....

What about throwing two CPU dies on one package, and using something like a high-speed hypertransport link between the two of them. I think I remember reading an article about this awhile back, but can't remember. That'd work, right?

[elmers]

"While technically/theoretically possible" umm no. Actually this isnt theoretically possible. In order to use two or more cpus on a single task it needs to be split up. Some problems can be broken down some cant.

[elmers]

http://www.cs.ualberta.ca/~hoover/P-complete/

[GameManK]

While technically/theoretically possible, I wouldn't do it. FSB speed anyone? You'd have to have a massive, massive pipe between the procs in order for it to work, about 4Ghz in fact. With just 800Mhz or so, you might as well fuggedaboutit.

Well that sucks. How did those dual processors video cards work then?

i know nothing about this, but i think it works on video cards because they don't run on such high clock speeds. If arcticfox is right, connecting two 250mhz-ish processors is much more reasonable than connecting two 2ghz processors.

[ArcticFox]

Originally posted by beppodmime
Well, kinda sorta like having two physical, identical processors....

What about throwing two CPU dies on one package, and using something like a high-speed hypertransport link between the two of them. I think I remember reading an article about this awhile back, but can't remember. That'd work, right?

That form of MP is called CMP (Chip Multiprocessing), and IBM's Power4 processor uses this method. Read up about that chip, and be amazed.

[ShawnD1]

If Intel and AMD don't do it, there must be some horrible catch. Is the production cost outrageous?

[poopeyhed2]

Originally posted by beppodmime
Well, kinda sorta like having two physical, identical processors....

What about throwing two CPU dies on one package, and using something like a high-speed hypertransport link between the two of them. I think I remember reading an article about this awhile back, but can't remember. That'd work, right?

AMD will be doing that to the Opteron's. It'll be pin compatible and all the great features of ther Opteron. What's cool about it is that you buy one chip and it's an automatic dual processor.