NF200 or not?

[NeedForSpeed73]

Hi everybody, I'm about to move my Triple-SLI of 280GTXs from Core 2 to Core i7. As many of you already know, X58 chipset provides enough electric channels only for two PCI-Ex 2.0 16x slots, so on motherboards with three 16x slots when all of them are populated two of them revert to 8x; to get around this limit manufacturers could use the Nvidia NF200 bridge and be able to provide 3 full 16x slots.
I've read in many posts this assertion: "8x will provide enough bandwidth for any VGA on the market atm"; but this articleseem to show that the above is not quite right with a whopping 33-50% advantage on the 16x slots in some situations.
Otherwise this review shows quite good numbers for Triple-SLI even on a 16/8/8 mobo.
So, is it worth waiting for the first (if ever) NF200 boards? Provided that the NF200 produces lot of heat and a Tri-SLI rig gets quite hot by its own and adds also some latency on the bus itself, if the 280GTXs wouldn't be bandwidth limited on the 8x slots i'd go without the NF200 very happily (and save a few bucks too).

 

[BTRY B 529th FA BN]

Is it stable?

and welcome to the Anandtech Forums btw

 

[nenforcer]

Well from my understanding there is more of a difference between x16 slots and x8 slots than there is between PCI-Express 1.0 and 2.0 slots of any speed.

So there is quite a difference between 650i and 680i boards and 750i and 780i, for instance, in which the "budget" 650i and 750i cut out PCI-Express channels.

Apparently this makes a bigger difference than the pure bandwith differences between PCI-Express 1.0 and 2.0.

If I was you and had a triple GTX 280 SLI setup I wouldn't accept anything less than and x58 board WITH the NF200 chip. It appears nVidia puts quite the incentive to have this chip for running triple or quad SLI.

Of course, I would wait until both kinds of boards are out before making this decision.

I own a 680i board and just upgraded to SLI for the first time BTW.

 

[Hauk]

i7 appears to offer a staggering gain for multi-gpu scaling. With that said, if you'd be willing to give up one card, you could choose a board that can run either 16x16 or 16x8x8. Two 280's scaling well without cpu limitiation would still kick major ass. Expensive but available right now is this puppy..

"The Rampage II Extreme supports the PCI-Express 2.0 standard as well as earlier PCI-Express 1.0a/1.0 compliant devices. The board features three PCI-Express x16 slots. They can run in a 16x16 configuration or a 16x8x8 configuration. As I mentioned earlier the board supports ATI's Crossfire and CrossfireX technologies as well as NVIDIA's SLI, 3-Way SLI and Quad-SLI technologies." Source

In stock at time of post for $410

I'd guess it'll carry a $399 price once the Egg and others carry it.

 

[NeedForSpeed73]

Originally posted by: nenforcer

Well from my understanding there is more of a difference between x16 slots and x8 slots than there is between PCI-Express 1.0 and 2.0 slots of any speed.

So there is quite a difference between 650i and 680i boards and 750i and 780i, for instance, in which the "budget" 650i and 750i cut out PCI-Express channels.

Apparently this makes a bigger difference than the pure bandwith differences between PCI-Express 1.0 and 2.0.

AFAIK apart from the power supply characteristics (PCI-Ex 2.0 can supply much more watts via the slot), the main difference between 1.0 and 2.0 is the clock speed they are working at (100Mhz vs 250Mhz). Doing some very rough calculations PCI-Ex 2.0 8x might even be faster than PCI-Ex 1.0 16x (half channels but at more than doubled speed).

Originally posted by: nenforcer
If I was you and had a triple GTX 280 SLI setup I wouldn't accept anything less than and x58 board WITH the NF200 chip. It appears nVidia puts quite the incentive to have this chip for running triple or quad SLI.

Of course, I would wait until both kinds of boards are out before making this decision.

I own a 680i board and just upgraded to SLI for the first time BTW.

That's for sure! Problem is that Tri-SLI is not so common configuration so dunno how many reviews will be around comparing boards w/NF200 and wo/NF200...

 

[NeedForSpeed73]

Originally posted by: SteelSix
i7 appears to offer a staggering gain for multi-gpu scaling. With that said, if you'd be willing to give up one card, you could choose a board that can run either 16x16 or 16x8x8. Two 280's scaling well without cpu limitiation would still kick major ass. Expensive but available right now is this puppy..

"The Rampage II Extreme supports the PCI-Express 2.0 standard as well as earlier PCI-Express 1.0a/1.0 compliant devices. The board features three PCI-Express x16 slots. They can run in a 16x16 configuration or a 16x8x8 configuration. As I mentioned earlier the board supports ATI's Crossfire and CrossfireX technologies as well as NVIDIA's SLI, 3-Way SLI and Quad-SLI technologies." Source

In stock at time of post for $410

I'd guess it'll carry a $399 price once the Egg and others carry it.

I've seen that "staggering gain" too and i was surprised by that: before seeing these first reviews I was even thinking to skip first Nehalem wave (1366) because many people on forums were sure that i7 architecture wouldn't have been a big improvement for games due to the fact that most today's games are coded for the consoles and then just ported to PC, and so they are quite completely single threaded and they'd not benefit from the high parallelism of Nehalem.

Don't tell me to give-up TriSLI for SLI: I don't want that at all, and for my way of gaming (I love to have high AA and AF) GPU power is much more important than CPU.

 

[Hauk]

Yea I'd prolly feel the same way if I already had three 280's.

Will you'll have to choose a board with a PCI-E 1x slot located above the primary PCI-E slot for sound? I'm looing at following pics, three 280's cover everything!

Naked evga and populated..

Here's a thread with various board info

Please update when you've made a selection. I was stressing over the choice but will only be 2-card so I went with the Rampage II. Welcome to AT.

 

[Zap]

Originally posted by: SteelSix
Naked evga

Heh, to use any other slots with three GTX 280, you'd have to watercool the cards with single slot blocks. Too bad EVGA's own cards aren't quite single slot. Good thing there are other brands that are.

 

[sxr7171]

Originally posted by: NeedForSpeed73

Originally posted by: SteelSix
i7 appears to offer a staggering gain for multi-gpu scaling. With that said, if you'd be willing to give up one card, you could choose a board that can run either 16x16 or 16x8x8. Two 280's scaling well without cpu limitiation would still kick major ass. Expensive but available right now is this puppy..

"The Rampage II Extreme supports the PCI-Express 2.0 standard as well as earlier PCI-Express 1.0a/1.0 compliant devices. The board features three PCI-Express x16 slots. They can run in a 16x16 configuration or a 16x8x8 configuration. As I mentioned earlier the board supports ATI's Crossfire and CrossfireX technologies as well as NVIDIA's SLI, 3-Way SLI and Quad-SLI technologies." Source

In stock at time of post for $410

I'd guess it'll carry a $399 price once the Egg and others carry it.

I've seen that "staggering gain" too and i was surprised by that: before seeing these first reviews I was even thinking to skip first Nehalem wave (1366) because many people on forums were sure that i7 architecture wouldn't have been a big improvement for games due to the fact that most today's games are coded for the consoles and then just ported to PC, and so they are quite completely single threaded and they'd not benefit from the high parallelism of Nehalem.

Don't tell me to give-up TriSLI for SLI: I don't want that at all, and for my way of gaming (I love to have high AA and AF) GPU power is much more important than CPU.

I don't know. Except for the Wii all modern consoles have multiple cores.



Agree that GPU is more important for gaming, but CPU is important for all sorts of other things. Transcoding, encoding etc.

 

[lopri]

I wish TweakTown would take down that article or rerun the test with a right board/BIOS.. Everyone refers to that article when it comes to x8 vs. x16 despite dozen other reviews saying otherwise.

 

[jandlecack]

Forget about the NF200. It's a gimmick that will decrease your performance compared to the same x58 setup because it adds another component in between PCI-E and CPU that just adds latency.

In theoretical terms, the NF200 *could have* improved performance if it was actually implemented the way it is advertised. But instead, the lanes may be x16-x16-x16, but the interface that finally reaches the other components is still limited at x16-x8-x8 because of the x58 architecture. From my understanding the NF200 is just added on top of the x58 which still bundles the latter two PCI-E lanes into one x16, thus halving the bandwidth after all.

http://www.lanified.com/Media/ghetto_x58_nf200.JPG

This NF200 component as you can see above is just inserted in between, lowering effectively what you should be getting out of your system.

Edit: Check HardOCP for a recent GTX280 Tri-Sli comparison. Their x58 test system (I believe P6T Deluxe, or the R2E) beat the NF200 test system (ASUS P6WS Revolution).