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."

32x

[Ann Coulter]

The PCI Express standard allows for 32x lanes. The nVidia SLI uses two 8x lanes. Wouldn't it be nice if a motherboard supported two (or more) 32x lanes and 32x graphics cards working in parallel? Think ray tracing because at those bandwidths, and the fact that there is a ergonomic limit on how small a pixel on a display can be, one can have the average size of a triangle be smaller than a pixel. This isn't true ray tracing but the effect is there.

On a similar note, are GPUs a good platform for genuine ray tracing?

GPGPU

[ryanmfw]

This is actually a very interesting possibility for general purpose GPU programming, which aims to offload as much easily parallelizable operations off to the video card. If you can have two, running off of PCIe, you could get a big return in speed, allowing some very cool stuff to be done much quicker.

Check out http://www.gpgpu.org/ [gpgpu.org] for cool stuff. And if I'm not mistaken, it is already possible to use SLI.

Cheers,

Re:SLI != SLI

[Anonymous Coward]

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.

Why don't they render the left and right side instead of top and bottom? Is it because it's easier to sync with the beginning of the horizontal sweep of a CRT?

SLI is a rip off.

[Anonymous Coward]

I'll wait for the dual GPU on a single card solution. You gain nothing from having 2 cards, the dual PCI express boards still have the same bandwidth the lanes are just split between the two.

This simply forces you to get a new motherboard. Which I guess is a win for intel and nvidia eh?

Let's see, get dual cards which requires a new motherboards, or wait and get a new video card that has gual GPU"s which takes about 10 minutes to install at most.

I bet you ATI will do the dual GPU solution first and nvidia will go "fuck we should have learned from 3dFX's voodoo 5500"

I had a 5000 series card, dual Gpu's on the SAME card amazing concept!

The dual voodoo cards made sense in a day when you had a lot of spare pci slots. But ever since we've gone to the methodolgy of a single graphic slot it's not simply a matter of slapping in a new video card and connecting an sli connector, you have to get a whole new motherboard.

I DO agree with a previous statement made that is if we could go up to 4 cards and 4 cpu's on a system. that kind of flexibility would be awesome.

Re:Double The Money

[Raptor CK]

More like, "Hey, the last generation videocard is now obsolete, and no one wants it! How do we fix this next time?"

"I know, let's make it so that if you buy a second one a year later, it'll work WITH the first one!"

No one needs to buy two right off the bat. One is usually more than enough for any modern game. But one for a few hundred now, and the other for less than $100 later? That's a bargain basement upgrade, and one that's far more sensible than getting the new mid-range card now, and the new mid-range card a year from now.

Now, if someone *wants* to buy two top of the line cards today, more power to them. They want the ultra-high-resolution games with all the effects cranked up, and they have the money. It makes their games look nicer, while my games run well enough. We both win, and Nvidia no longer sits on piles of unused chips.

Re:New trend ?

[cplusplus]

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

A long time ago I had an Obsidian X-24 graphics card, which was basically an SLI Voodoo2 on one card that drew its power from a single PCI slot. It used so much power that that my computer would just power off without warning quite frequently.
A 350 watt power supply fixed the problem (I had a 250 watt), and that was a LOT of power back then. Now I have a 400 watt Antec power supply which was the recommended solution for my AMD. I think in a year or so that 500 watts will be commonplace.

Possible reason...

[apharov]

Would you happen to be using a motherboard with a VIA chipset? My old MB used a KT400 chipset. I didn't notice anything strange when using a Radeon 7200 on it but when I upgraded to a 9800Pro the speed I got was way slower than what it should have been. A couple of nights on tweaking and googling and I came to the conclusion that KT400 AGP support was s**t, especially with ATI video cards.

One more night of examining other motherboards and I decided to buy a mb based on nForce2Ultra chipset. After installing the new mb my actual FPS's almost doubled. Bying a new mb might seem a bit drastic but considering that it cost "only" ~120e vs. the 250e of the R9800Pro it seemed quite reasonable to me and I haven't regretted it.

Personally I will never use VIA's chipsets again if I have any other choices.

Re:New trend ?

[owlstead]

Of course some might question whether a siamesed pair of processors actually constitutes a single IC.....

As long as the software developers do (with their crazy per-processor schemes it doesn't matter. Microsoft got that right in one go (I still don't like them, but they seem to do more right lately). Others will probably follow suite, at least for the PC/small server market.

And the rest is academic. Call it what you like, as long as it speeds up my PC and gives me better response time? Since the processors do share resources on the IC - and it's almost impossible to not share some resources - lets call it one IC (and anyway, IC means integrated circuit, does say nothing on what the circuit constitutes).