Lookie

[Hamma]

The SLI gives you more power. Kind of like putting a supercharger on your whip.

Although quad SLI may be a bit overkill at this point

[Rbstr]

Originally Posted by Hamma

The SLI gives you more power. Kind of like putting a supercharger on your whip.

Although quad SLI may be a bit overkill at this point

Two flagship cards are already overkill, four is like killing a ant with a howitzer.

[Electrofreak]

Agreed. The human eye can't tell the difference between 200 and 300 FPS, and a good high-end card will give you enough FPS anyhow in modern games. All 4 cards will do is buy you a couple years without needing to upgrade, though I'd rather spend a couple hundred bucks every year to keep a new video card in my computer than a grand every 4.

[OneManArmy]

even though I totally agree that any more than one card is bullshit...

don't underestimate the human eye

If this old United States Air Force study is any clue to you, we've only scratched the surface in not only knowing our FPS limits, and coming up with hardware that can match, or even approach them.

The USAF, in testing their pilots for visual response time, used a simple test to see if the pilots could distinguish small changes in light. In their experiment a picture of an aircraft was flashed on a screen in a dark room at 1/220th of a second. Pilots were consistently able to "see" the afterimage as well as identify the aircraft. This simple and specific situation not only proves the ability to percieve 1 image within 1/220 of a second, but the ability to interpret higher FPS.

[Electrofreak]

true, but thats a big difference between having a visual difference between 200 and 300 FPS. Some people will say that 60 FPS is the point where something stops looking like a rapid series of pictures and becomes a smooth flowing scene. Personally, I can tell when a screen is flickering at less than 85 Hz (drives me nuts) so I know that can't be 100% correct. But the point is, is there any significant visual difference between 200 and 300 FPS? Doubtful, or if there is, I can't tell. I can see the validity of dual cards to a degree because some games with maxed graphics can make even the best modern video card struggle to achieve a steady 80 FPS, but dual cards solves that problem rather easily. Additionally, I'd rather not waste space inside my computer for multiple cards.

Secondly, a question to the folks who have been keeping up on SLI. It would seem that despite having 2 cards, your video memory would remain the same. I mean, both cards have to load all the textures. If you have 2 128 mb cards, you don't get 256 mb of video memory right? Another reason why I'd stick with a single high-end card with which I could replace at more frequent intervals. Newer cards often include advances in technology aside from simple increases in memory and processing speed as well, which is why I'd rather not chain myself to a multiple set of cards.

[Marsman]

As I understand the SLI process, each card takes a turn at painting part of the screen via a variety of methods (interlace, dynamic upper and lower, etc...). Therefore, I would think textures would have to be loaded in both cards and yes total video memory would be doubled. Some games respond to SLI better that others - if fact some games actually run slower in SLI than with a single card. It all depends on how they've coded the game. In most cases, yes there is significant FPS improvement but it's still a tad early in the SLI game same as the dual core CPU game and untill more games are coded to specifically handle these situations, a single good graphics card is probably the way to go. Hey you can always add another down the road at any time too.

[OneManArmy]

well considering games are usually codded to the lowest common denominator... ts gonna be a long time before thats ever the standard.

besides anyone remember hooking up 2 voodoo 2s together? my rig was da shit with that. like 10 years ago

[Electrofreak]

Originally Posted by Marsman

As I understand the SLI process, each card takes a turn at painting part of the screen via a variety of methods (interlace, dynamic upper and lower, etc...). Therefore, I would think textures would have to be loaded in both cards and yes total video memory would be doubled. Some games respond to SLI better that others - if fact some games actually run slower in SLI than with a single card. It all depends on how they've coded the game. In most cases, yes there is significant FPS improvement but it's still a tad early in the SLI game same as the dual core CPU game and untill more games are coded to specifically handle these situations, a single good graphics card is probably the way to go. Hey you can always add another down the road at any time too.

I think you're right, and I agree with what you're saying Mars, I also heard that they each render a part of the screen... but if they both have to load all the textures individually then wouldn't that mean the video memory WOULDN'T double? If they could share their video memory as a common pool, and the video cards could access textures out of the other's memory, then I could see video memory being doubled. Its kinda like a series/parallel kinda thing if you know what I mean. Thats what I'm really trying to figure out.

[eXoSloth]

Film is only 24 fps...

[OneManArmy]

Originally Posted by eXoSloth

Film is only 24 fps...

there's also motion blur present in movies.. makes it look fluid.

[Marsman]

Originally Posted by Electrofreak

I think you're right, and I agree with what you're saying Mars, I also heard that they each render a part of the screen... but if they both have to load all the textures individually then wouldn't that mean the video memory WOULDN'T double? If they could share their video memory as a common pool, and the video cards could access textures out of the other's memory, then I could see video memory being doubled. Its kinda like a series/parallel kinda thing if you know what I mean. Thats what I'm really trying to figure out.

This is a good question and I don't know for sure how they deal with that. I would suspect that each card would load into memory the textures that are required for its "share" of the screen render. While this may indeed duplicate some textures I suppose it's possible, in certain views, that a card would only load the textures it needed for it's section of the screen and thus "could" be independent.

As for sharing memory between the cards, I dunno if that's possible or being done. Would seem to me that it might create a pretty intense amount of traffic on the PCIe buss but I guess it's conceivable. Would have to go back and read up on all that SLI stuff again and pay a little more attention to the details. I do remember, from a read of all the SLI info, that there were a fairly large number of methods SLI operated under from simple top half - lower half, to interlace, and then some pretty exotic methods too complex for me to recall but the basic premise was the work load for rendering a screen was split up and very well might involve a shared memory situation.

[Electrofreak]

Indeed, I need to hit the books on some of this new technology, I haven't been holding very faithful to my Computer Science major.

[OneManArmy]

thats because this sli shit should hopefully die out like the connected voodo 2s did.

i mean just wait till we need physic processor cards.. you really want to pay for 2 3 or 4 gfx cards too? id buy a console first.....

[Electrofreak]

The Physics card interests me, theres a card called PhysX that will be released Soon(tm) that is supposed to dramatically improve game performance in games that support the card (the Unreal 3 engine and City of Villans are examples).

I think its a cool concept, anything that encourages developers not to hold back in programming realistic physics into games is more than welcome in my book. As it is, many physics intensive games are limited by your CPU's ability. You can have the best graphics card possible and if you don't have a good CPU, you won't have good performance. The card offloads some of that physics processing off of your CPU onto the card, giving you a bit more breathing room.

[AztecWarrior]

It runs Doom 3 at 40 FPS, I swear.