Running Video Cards in Parallel

G.A. Wells writes "Ars Technica has the scoop on a new, Alienware-developed graphics subsystem called Video Array that will let users run two PCI-Express graphics cards in parallel on special motherboards. The motherboard component was apparently developed in cooperation with Intel. Now if I could only win the lottery."

Comments

Big Deal - PCI Express. Any one can add two video

[liquidzero4]

So what technology did Alienware create here? None..

So they have one of the first MB's with two PCI Express slots. Big deal, soon MB's will contain many PCI-Express slots. Hopefully a lot more than 2.

Oh, come on!

[Short Circuit]

All you really need is some way to copy the data in memory from one card to another.

Easy solution? Several high-speed serial connections in parallel between the two cards. With a little bit of circuitry on the card dedicated to keeping the data identical.

Or, with a little bit of a performance hit, you could keep each section of RAM separate, and route misses over the cables.

Power to them if they can pull it off!

[l33t-gu3lph1t3]

discrete parallel graphics processing has been around for a while. The most notable example of it is probably 3DFX and their Voodoo-2 cards. However, there's a problem with this tactic, namely, in the "diminishing gains" department.

So here's the question:

-How is pixel processing going to work? For a given frame, there is vertex, texture information, as well as the interesting little shader routines that work their magic on these pixels. How are you going to split up this workload between the 2 GPUs? you can't split a frame up between the GPUs, that would break all texture operations and there would be considerable overhead with the GPUs swapping data over the PCI bus. *MAYBE* having each gpu handle a frame in sequence would do the trick, but, again, it's a dicey issue.

It would appear to me that this dual-card graphics rendering is quite similiar to dual-gpu graphics cards. Except, where in a graphics card you can handle cache/memory coherency and logic arbiting easily due to the proximity of the GPUs, with this discrete solution you run the problem of having to use the PCI Express bus, which, as nice as it is, is certainly not that much faster than AGP.

So I say, power to you Alienware. If you can pull it off with Nvidia, ATi et all, great. It's too bad the cynical side of me thinks this idea reeks of those blue crystals marketing departments love :)