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

In other news...

[Unloaded]

...Microsoft announced that Clippy had broken the before unheard of 2,000 fps barrier.

Re:In other news...

[david.given]

Microsoft announced that Clippy had broken the before unheard of 2,000 fps barrier.

However, they went on to say that Clippy was still intact. They're going to try again using a bigger catapult and with a concrete-reinforced barrier.

Man am I out of the loop.

[Randolpho]

PCI-Express? What happened to AGP?

Seriously, I've been out of the PC market for too long. Alas, poor wallet. I had cash flow, Horatio.

Re:Man am I out of the loop.

[Laebshade]

PCI-Express is meant to replace AGP. From what little I've read into it, it will require lower voltages than AGP and has a wider bus.

Re:Man am I out of the loop.

[Randolpho]

After I posted that, I did a quick google:

http://www.pcworld.com/news/article/0,aid,94724,00 .asp

Re:Man am I out of the loop.

[Plutor]

You've been out of the PC market for about a decade then, if you've never heard of PCI-Express. It's been proposed and talked about and raved about for years, but it's just now finally coming to market. The best thing is that it's not limited to a single slot per board! That's why this parallel thing is even possible.

Re:Man am I out of the loop.

[Auntie Virus]

There's a White Paper on PCI Express from Dell: Here

Re:Man am I out of the loop.

[The_K4]

Since the PCI-Express spec defines switches (these are like P2P-bridges only they have 2 sub-buses) a mother board manufacturer could add 2 of 3 of these and get 4 PCI-Express Graphics ports (or 7 and get 8 ports) the problem is that every time you do this you have to share the total bandwidth at the highest level. Since PCI-Express does have more bandwidth the AGP 8x and 1/2 of that bandwidth is dedicated up the other 1/2 dedicated down. So the down-stream (where video cards use most of their bandwidth) is greater the AGP8x's TOTAL bandwidth. So this data path bottle next shouldn't be bad if you have 2 cards (might work well for 4 if they use the bus right).

Re:Man am I out of the loop.

[WuphonsReach]

You've been out of the PC market for about a decade then, if you've never heard of PCI-Express.

That's rather over-stating the case.

Roughly 10 years ago, PCI was finally just supplanting EISA/VESA and ISA boards were still common.

I build a few machines per year, and PCI-Express only just hit my radar screen in the past 12-18 months. Even today, I have yet to see mainstream motherboards or cards for it, so it's still rather ephemeral at this point.

It is an interesting design. Whether or not it will live up to it's promise remains to be seen.

Quad-screen?

[Vrallis]

Hell, I couldn't care less about parallel processing for the video cards.

I want tri-head or quad-head video, but with at least AGP speeds. You can do it now, but only with PCI cards getting involved.

Re:Quad-screen?

[houghi]

I want tri-head or quad-head video, but with at least AGP speeds

So order one now. They are available here at Matrox.

Re:Quad-screen?

[RhettLivingston]

As long as you can live with at least one of the screens not running quite as fast (maybe an informational type of screen as opposed to 3D scenery?), 3 screens ia really easy today. Almost all decent AGP cards these days support 2 screens at 1600x1200. Throw in a good PCI card and you've got 3. I've been running this way for years and it works well. Actually, the PCI card isn't shabby.

The only problem I encounter in Windows is an occasional tooltip coming up on the primary monitor instead of a secondary monitor. This is not the fault of the OS, rather the application is constraining the tooltip to be on the primary monitor by forcing it to be within the primary monitor's coordinates.

Note that Matrox's single board AGP solution does not compete with this. Using a high end NVidia for the main two screens provides too much of a performance advantage to give up for Matrox's slow cards. Matrox's cards, even though on AGP, run about like the PCI cards.

Regardless, when these systems become more available, I will be one of the first to put 2 video cards in and run 3 or 4 screens from my PCI Express system. But, though I like playing 3D games this way, I do it for the extra informational surface for programming. It greatly eases things to run your application on one screen and your development environment on all of the others so that you can see everything at once. And with 19" 1920x1440 monitors (which usually manage 1600x1200 with better focus than a 1600x1200) running around $250 a pop, its a very worthwhile investment.

Press Release

[Anonymous Coward]

over here: clicky

Voodoo

[Eu4ria]

Didnt the early voodoo cards allow something similar to this ? I know they had a pass through from your 'normal' video card but i seem to remember the ability of running more and they would each do alternating scan lines.

Re:Voodoo

[scum-e-bag]

The company was 3dFx, and it was thier Voodoo II cards that allowed the use of two cards a few years back, sometime around 1998 IIRC.

Re:Voodoo

[naoiseo]

without a special motherboard, yes.

I think you could string something like 4 voodoo rush cards together or something (who knows if you got 4x performance, but I'm sure it went up not down)

Problem was, by the time they put this out there, the tech it was running was months behind cutting edge. 4x something old is easily forgotten.

Re:Voodoo

[UnderScan]

SLI - scan line interleve, was available for 3dfx Voodoo IIs (maybe even Voodoo 1) where the first card would process all the odd lines & the second card would process all the even lines.

Re:Voodoo

[kamelkev]

Voodoo was basically the beginning of the performance PC market, with tons of wierd options and card types.

Benchmarks for the old 3dfx V2 SLI can be seen here:

http://www4.tomshardware.com/graphic/19980204/

I was (and still am, although its in the junk pile) a 3dfx V2 owner, the performance of that card was just amazing at the time. The Voodoo and the Voodoo2 definitely changed the world of 3d gaming.

Also of interest is an API that came out much later for the 3dfx chipsets that actually let you use your 3dfx chipset (they didn't call it a GPU back in the day) as another system processor. If you were an efficient coder you could actually offload geometric and linear calculations to the card for things other than rendering. I can't seem to find the link for that though, it may be gone forever.

Re:what will this do?

[m4vrick]

Now you can play solitary and minesweaper at the same time on a maximized screen. :)

interesting technology

[cheese_wallet]

I think it is great that a company has the will to do something like this, even if it doesn't catch on. It's cool to try something new, instead of just hanging back and doing the tried and true.

I'll admit I haven't yet read the whole article, but even though it says that it isn't tied to any one video card, that doesn't say to me that it can have multiple disparate cards. If it is doing something along the lines of SLI, I would guess that the speeds would need to be matched between the two cards. And that would imply having two of the same card, whatever card the user chooses.

But maybe not... maybe it's the advent of asymetric multi video processing.

Re:interesting technology

[jonsmirl]

You can do this today with Chromium.

Chromium replaces your OpenGL library with one that farms the OpenGL drawing out to multiple machines. It's how display walls are built.

You can use the same technique for multiple card in the same box.

this isn't new

[f13nd]

Alienware didn't invent this
the PCI and PCI Express have had this written into spec
AGP does too, but when was the last time you saw dual AGP slots on a mobo? (they do exist)

Re:this isn't new

[BenBenBen]

The AGP port spec lays it out; AGP is a preferred slot on the PCI bus, with four main enhancements (pipeline depth etc) designed to... Accelerate Graphics. Therefore, if you had more than one PCI bus, you could technically have more than one AGP port. However, I cannot find a single motherboard that offers 2 AGP slots, including looking in numerous AV/editing specialists, where I'd expect this osrt of thing to tip up.

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.

Nice, A complete Vapor-article.

[Gr8Apes]

From the article: "The answers may have to wait until Q3/Q4". There are no performance numbers, no real statements of how it works, nothing much at all. Just wow, gee whiz, dual graphics cards in parallel. What exactly does "in parallel" mean? That's not even addressed.

Some things I thought of immediately reading this, great - two displays each driven by a separate card, or, better yet, quad displays driven by two cards. Nope, not a word about either possibility. The implication of the PR/article is that 3D graphics will be processed faster. How? Do they have some nifty way of combining two standard off the shelf graphics card signals into a single monitor? (Hint, it's hard enough getting the monitor to properly synch up with a single high performance graphics card!)

Since when does ArsTechnica merely regurgitate PRs? This was 99.999% vacuum.

Are we going to need this...

[CodeMonkey4Hire]

for Longhorn?

Re:Next comes dual AGP graphics.

[DaHat]

Nay, the AGP standard is built around a single slot and a single graphics card. To permit two AGP cards running natively (via the AGP bus) in a single system would be quite difficult if not impossible, far easier to look to the future and a new technology to make it work better then any sort of hack job that could be done today.

The real question

[241comp]

Is this compatible with Brook and other general-purpose GPU programming techniques? The use I see for it is this:

Imagine an openmosix cluster of dual-processor machines that run bioinformatic calculations and simulations. Lots of matrix math and such - pretty fast (and definitely a lot faster than a single researcher's machine).

Now imagine the same cluster but each machine has 2 or 4 dual-head graphics cards and each algorithm that can be created in Brook or similar is. That gives each machine up to 2 CPU's and maybe 8 GPU's that may be used for processing. The machines are clustered so a group of ~12 commodity machines (1 rack) could have 24 CPU's and 96 GPU's. Now that would be some serious computing power - and relatively cheap too (since 1-generation old dual-head cards are ~$100-$150).

By the way, does anyone know if there is any work going on to create toolkits for Octave and/or MatLab which would utilize the processing power of a GPU for matrix math or other common calculations?

The Return of Voodoo 2 SLI

[MoZ-RedShirt]

History repeating: Who can (or can't) remember

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 :)

Re:How is this different than what I've been doing

[IAmAMacOSXAddict]

If you read the short article. they are talking about pushing all the data for a SINGLE monitor, through two PARALELL cards. Essentially allowing for twice the GPU power to crunch the graphics for the monitor.

You are running a bunch of video cards INDEPENDANT of each other. Clearly NOT THE SAME THING...

Re:Next comes dual AGP graphics.

[Jeremy Erwin]

It's in the AGP 3.0 spec.

AGP3.0 allows a core-logic implementation to provide multiple AGP3.0 Ports. Each AGP3.0 Port is a bridge device with multiple AGP3.0 devices hanging off the secondary bus. Each Port has a separate Graphics AGP aperture and GART that is independent and not shared with another AGP3.0 Port; however, these are shared across the devices within a single AGP3.0 Port.

ATI will be doing this it's Catalyst drivers soon

[89cents]

Ok, so they havn't explicitly said so, but have been hinting at it

Ati's Terry Makedon says: "Something big is coming for CATALYST in the next 2-3 months. It will take graphic drivers to a brand new level, and of course will be another ATI first. It will be interesting to see how long before other companies will copy the concept after we launch it."

Hmmm... just in time for PCI Express and it's not something specifc to Ati's hardware.