Dual Video Cards Return

Kez writes "I'm sure many Slashdot readers fondly remember the era of 3dfx. SLI'd Voodoo 2's were a force to reckoned with. Sadly, that era ended a long time ago (although somebody has managed to get Doom III to play on a pair of Voodoo 2's.) However, Nvidia have revived SLI with their GeForce 6600 and 6800 cards. SLI works differently this time around, but the basic concept of using two cards to get the rendering work done is the same. Hexus.net has taken a look at how the new SLI works, how to set it up (and how not to,) along with benchmarks using both of the rendering modes available in the new SLI." And reader Oh'Boy writes "VIA on its latest press tour stopped by and visited in the UK and TrustedReviews have some new information on VIA's latest chipsets for AMD Athlon 64, the K8T890 and the K8T890 Pro which supports DualGFX. But what has emerged is that DualGFX after all doesn't support SLI, at least not for the time being, since it seems like nVidia some how has managed to lock out other manufacturers chipsets from working properly with SLI. VIA did on the other hand have two ATI cards up and running, although not in SLI mode."

Intel & SLI

[DeadBugs]

It is worth noting that NVIDIA will be bringing SLI to the Intel platform according to this press release:

http://www.nvidia.com/object/IO_17070.html [nvidia.com]

I'm looking forward to a P4 NForce board.

AlienWare

[Spez]

You can already buy from the alienware luxury collection some gaming systems featuring SLI

http://www.alienware.com/ALX_pages/choose_alx.aspx [alienware.com]

SLI != SLI

[Jahf]

First it is mildly interesting to note that SLI from Voodoo was "scan-line interleaving", as in every other line was alternated between the 2 cards. Nvidia SLI is "scalable link interface" and instead renders the top half of the image on one and the bottom on the other.

It does make me wonder if the technology is capable of truly scaling ... ie ... more than 2 cards? Could be useful for scientific simulations or even getting closer to the idea of "ToyStory in realtime" (and no arguments here ... using the same shaders as Pixar used in the movies in realtime is not feasible today ... cheap tricks to get close, maybe).

However, given the cost, and looking at what the 6800 can handle by itself, and comparing -those- to the evolution of games it appears to me that it will be no more costly to simply upgrade to a 6900/7000/whatever when it is required, as I can easily get by for the next year or two on a 6800 Ultra especially if including the fact that I would need a new computer to run it on since I don't have PCI-E (though I do have PCI-X, but not for gaming needs). And will be saving on electricity and mean time to failure (though that doesn't seem to be an issue much with video cards).

Not saying I don't see the attraction, but I don't get anywhere NEAR interested in 3D gaming enough to be spending that kind of dough.

Re:SLI?

[sjaskow]

SLI = Scan Line Interleave, the cards alternate drawing lines on the monitor.

Re:SLI?

[stratjakt]

Scan Line Interleaving.

Two video cards, one draws all the even scan lines for the final display, and one draws all the odd ones.

Re:this is sweet

[stratjakt]

No, it doesn't work that way.

Each card renders half of the same image. So each card needs access to the full texture set.

So 2x256 cards still only gives you 256 megs for your textures.

Ouch on Costs!

[Evil W1zard]

I can't imagine shelling out another couple hundred bucks for another XT pro and then shelling out even more money for a more robust power supply and better cooling as well. Its prolly great for those who can afford it, but I know I won't be doubling up anytime soon.

See also the UK "PC Pro" magazine

[Pete (big-pete)]

This month the UK "PC Pro" magazine has a review [pcpro.co.uk] of the Scan White Cobra [scan.co.uk] gaming machine.

This is a fine example of SLI running with jaw dropping performance...a quote from the review puts Doom 3 running at 98fps!

Now I know what I want for Christmas, just not a snowball's chance in hell of getting one! :)

-- Pete.

Re:SLI?

[Gates82]

Not true anymore. The new SLI format does not stand for the scanned lin..... Rather then having one video card take odd lines and the other even the cards actually break apart the frame to be rendered and determine where more detail (thus processing power) is need and the concentrate on those areas, so card one may be calculating more pixels, and card to might be concentrating on a detailed area, but they are both doing about the same amount of computation.

--
so really, who is hotter? Alley or Alley's sister?

Re:New trend ?

[Anonymous Coward]

Multiple GPUs will be good to have as there are lots of uses for GPUs additionally to pretty pictures.

The Folding@home (http://folding.stanford.edu/ [stanford.edu]) is about to enter the GPU based Folding:
http://forum.folding-community.org/viewtopic.php?p =75287#75287 [folding-community.org]

Interesting times ahead...

quadro

[Anonymous Coward]

High-end Quadros [nvidia.com] have 512 MB RAM. plus, they're dirt cheap ;)

6073

[Anonymous Coward]

dollars....

Re:SLI?

[Gates82]

Hate to reply to my own post but here is a link. Nvidia SLI [nvidia.com] SLI = Scalable Link Interface

--
So really, who is hotter? Alley or Alley's sister?

Tom's Hardware also has a test

[Anonymous Coward]

Tom's Hardware also did [tomshardware.com]review the SLI setup.

Power consumption

[Hoi Polloi]

And we're not even speaking of how much power (wattage) these 'dual solutions' consume...

SLI power consumption can be significant! [anandtech.com]

Re:SLIing other GeForces

[mesach]

its only compatible with like cards capable of SLI, you cannot just throw 2 cards in your box and run the latest drivers and get SLI.

there is a bridge adapter for the cards, if you look around they apparently come in PCB and Ribbon styles, and connect to a funky new cutout on the PCB on top of the Card.

What about the nforce4?

[lrwx]

Other than the fact that this is old news. I would have figured that the focus would be more on the new nforce4 chipset http://www.nvidia.com/page/nforce4_family.html [nvidia.com] familiy. There are three board types in this family The Nforce4 Standard, the Nforce4 Ultra, and the Nforce SLI. As a matter of fact Asus is releaseing an sli board based on this right now called the A8N-SLI with a slew of added features that you could expect out of and asus board including dual gigabit ethernet ports! Why the via board is even being covered is beyond me the nforce is a much more better chipset. Here is a [H]ardOCP benchmark page here http://www.hardocp.com/article.html?art=Njk2 [hardocp.com]. Enjoy. ;)

Re:why so little support for gamers?

[meestaplu]

Right now, the answer is pretty simple. If you want a game to use multiple processors at the same time, you need to include more than one execution thread--the programmer has to divide the work in such a way that two or more processors can do it. It's quite hard to build a multithreaded game; there was some SMP support in Quake III, but it wasn't very stable and didn't provide a huge performance boost.

With a multithreaded application, you have to guard against strange bugs that are very, very hard to fix. If your multithreaded application runs into a deadlock every hundred thousand frames or so, it will be next to impossible to isolate, and production will end up being slower than it already is. While I'm sure that writing multithreaded games will happen in the near future, I don't think it will catch on very quickly.

Re:Power consumption

[gordyf]

That's comparing the entire system's loads, though, and not just the video cards themselves. That means that adding another video card and changing nothing else raised their entire computer's power usage by 35%. That's a fair amount.

Re:SLI != SLI

[JoeNiner]

First it is mildly interesting to note that SLI from Voodoo was "scan-line interleaving", as in every other line was alternated between the 2 cards. Nvidia SLI is "scalable link interface" and instead renders the top half of the image on one and the bottom on the other.

Actually, nvidia's solution does either [anandtech.com], based on their own testing of which performs better for a given game. The drivers include profiles of the 100 most popular 3D titles which state which technique to use.

Vsync

[Anonymous Coward]

Sounds like you have vsync enabled. Vsync drops frames so that the number of frames per second evenly divides the refresh rate of your monitor. Disabling it will get you back lots of performance.

Re:SLI != SLI

[man_ls]

Vertical sweep is measured in Hz.

Horizontal sweep is measured in kHz.

That, and the fact that CRT monitors lend themselves to horizontal divisions (top/bottom, not left/right) since they sweep top to bottom during refresh.

Re:New trend ?

[adler187]

No the Voodoo 6 6000 needed the external power brick because it had 4 chips. The 5500 had only 2 and the 4500 had 1.

From wikipedia [wikipedia.org]

My memory differs from the wikipedia, I seem to remember there being a Voodoo 4 4000 and I believe the 3dfx site listed it as the Voodoo 6 6000 and not a Voodoo 5 6000. Although most of my information was looking around on the 3dfx site back in the day so it may be they listed cards that weren't actually released (like the 5000 which I remember seeing there too). you can find pictures of it here [google.com]

Also according to the wikipedia entry, the Voodoo 6 6000 would have beat the GeForce 2 GTS but not the Ultra or the GeForce 3.

Re:I Feel Another Commercial Coming On

[obeythefist]

But... who buys P4 for gaming? AMD CPUs cost less and perform better in gaming situations at this point in time. Given the next round of CPUs to compare will be dual core, and intel is lagging a good solid year behind AMD on the technology front...

Read the articles. Look at the prices. Compare the benchmarks. Make the right decision.