Sli going cross card?

[Garric]

I remember reading something (maybe a rumor) that nVidia plans to release a patch that allows you to go SLI with different video cards at the same time. For example, a 6600GT with a 7800GT, and they don't have to be the same brand either. Is this a rumor or is this in development?

 

[Skin]

Doesnt sound like the manufacturers would want that to happen... I doubt it will ever come out any time soon.

 

[trinibwoy]

I remember reading something (maybe a rumor) that nVidia plans to release a patch that allows you to go SLI with different video cards at the same time. For example, a 6600GT with a 7800GT, and they don't have to be the same brand either. Is this a rumor or is this in development?

It makes no sense for Nvidia to put any effort behind mixing cards with different performance. AFR and SLI AA are rendered useless in that scenario since performance will be limited to the slower card - which is the same reason why ATi's master/slave setup is questionable.

Regarding using different brands of the same card - there were some rumblings about that but nothing definite yet.

 

[s10010001]

dosnt make much sence, but I would love to be able to use my 6800GT PCIe with a 7800GT. Like maybey if the 7800GT did the entire screen and the 6800 jsut helped some how

 

[Garric]

I don't know how it would work, but I always figured that having 2 cards, even if one was considerably slower than the other card, it would still help out, at least a little bit. For example, when the next gen of nVidia comes out w/ a 8800GT or something, and I buy it, w/ my 7800GT, it won't be just something I need to throw out, know what I'm saying?!

 

[trinibwoy]

I don't know how it would work, but I always figured that having 2 cards, even if one was considerably slower than the other card, it would still help out, at least a little bit. For example, when the next gen of nVidia comes out w/ a 8800GT or something, and I buy it, w/ my 7800GT, it won't be just something I need to throw out, know what I'm saying?!

The problem with this thinking is that AFR, SLI AA and SuperAA are designed around both cards being close in performance. Only SFR and Super-tiling can benefit from cards with large performance deltas.

There was a short blurb on this at Hexus today - http://www.hexus.net/content/reviews/review.php?dXJsX3Jldmlld19JRD0xNTA5

 

[pandora's box]

i could see the benefits of say card one rendering the scene and card two doing the HDR or something...

 

[trinibwoy]

i could see the benefits of say card one rendering the scene and card two doing the HDR or something...

You can't separate HDR from "rendering". It is part of the process.

 

[DejaWiz]

You can't separate HDR from "rendering". It is part of the process.

Well iirc (please correct me if I'm wrong), isn't HDR lighting performed "on the fly"?

Does anyone think it might be possible to develop a driver that would allow the faster primary card for scene rendering and the slower/older gen secondary to act like a dedicated HDR engine of sorts, kind of like how the new PhysX physics engine would help offload the CPU in that regard?

 

[MrGuvernment]

I remember reading something (maybe a rumor) that nVidia plans to release a patch that allows you to go SLI with different video cards at the same time. For example, a 6600GT with a 7800GT, and they don't have to be the same brand either. Is this a rumor or is this in development?

ATI is allowing that, not NVIDIA? - but NVIDIA i beleive was releasing a patch that allowed you to use the SAME CARD - but diff. brands, that is all i recall.

 

[trinibwoy]

Well iirc (please correct me if I'm wrong), isn't HDR lighting performed "on the fly"?

Does anyone think it might be possible to develop a driver that would allow the faster primary card for scene rendering and the slower/older gen secondary to act like a dedicated HDR engine of sorts, kind of like how the new PhysX physics engine would help offload the CPU in that regard?

I really don't understand what you mean. You're referring to "scene rendering" and "HDR" as if they are two separate and independent things. The NV40 doesn't render a scene and then "apply" HDR. The scene is rendered "in" HDR using an FP16 framebuffer with a tonemapping pass to bring it back to INT8.

 

[CMAN]

Nvidia is working on some drivers that will allow cards from different manufacturers and and different bios's. even Missfire requires cards of the same speed ie 800+800,850+850.

 

[DejaWiz]

I really don't understand what you mean. You're referring to "scene rendering" and "HDR" as if they are two separate and independent things. The NV40 doesn't render a scene and then "apply" HDR. The scene is rendered "in" HDR using an FP16 framebuffer with a tonemapping pass to bring it back to INT8.

Allright, I stand corrected. Thought I had read somewhere that HDR was rendered on the fly. Thanks for the info!

 

[Sly]

I remember reading something (maybe a rumor) that nVidia plans to release a patch that allows you to go SLI with different video cards at the same time. For example, a 6600GT with a 7800GT, and they don't have to be the same brand either. Is this a rumor or is this in development?

I doubt it. They're too architecturally different. All i've heard is allowing different manufacturers to connect. They might even be able to connect two different models and just give most of the load to the higher card (dynamic load balancing means you can theoretically give 30% to a 6600 and 70% to 6800, don't quote me on that tho). But different cores? No way.

 

[MrGuvernment]

I doubt it. They're too architecturally different. All i've heard is allowing different manufacturers to connect. They might even be able to connect two different models and just give most of the load to the higher card (dynamic load balancing means you can theoretically give 30% to a 6600 and 70% to 6800, don't quote me on that tho). But different cores? No way.

Well - if ATI can do diff, cores, why couldnt NVIDIA.

 

[CMAN]

Well - if ATI can do diff, cores, why couldnt NVIDIA.

Actually we dont know what ATI can do since theres no motherboard or video cards........

 

[Brent_Justice]

I remember reading something (maybe a rumor) that nVidia plans to release a patch that allows you to go SLI with different video cards at the same time. For example, a 6600GT with a 7800GT, and they don't have to be the same brand either. Is this a rumor or is this in development?

Cross Branding, not Cross Modeling

ForceWare 80 series

 

[trinibwoy]

Well - if ATI can do diff, cores, why couldnt NVIDIA.

That's the wrong question. The question is why "should" Nvidia. ATi is forced to since their crossfire cards are limited to certain SKU's. There is no "benefit" to allowing a X800GT to work with an X800XL CF card for example. Why would you want to mix and match cards of different performance levels anyway?

 

[trinibwoy]

Cross Branding, not Cross Modeling

ForceWare 80 series

Brent, any word on when these magical 80 series drivers will appear? Early/late September? Will there be performance improvements across the board or are we looking at mainly SLI compatibility and dual-core support?

 

[MrGuvernment]

That's the wrong question. The question is why "should" Nvidia. ATi is forced to since their crossfire cards are limited to certain SKU's. There is no "benefit" to allowing a X800GT to work with an X800XL CF card for example. Why would you want to mix and match cards of different performance levels anyway?

true - well, if you have one x800 Pro - and now you get an x800 XT (lead card) for a gerat price - yes it will only run @ x800 PRO speeds - but now you have 2 x800PRO's - and now, later if you get another Xt for a great price you upgradeb (sell the pro) - it is almost like you can upgrade one card @ a time

where as NVIDIA you want a new card - you have top buy 2 cards and try to sell 2 cards.

I guess for an upgrade purpose ATI seems more appealing - if they ever frick'n release it.

 

[trinibwoy]

I guess for an upgrade purpose ATI seems more appealing - if they ever frick'n release it.

Interesting proposition. Using the "Master" card as a leg-up for an upgrade does make sense. But you still have to consider the psychological impact of "knowing" one of your cards is running slower than it could even though you paid good money for it - I think that's going to be one of the biggest obstacles.

I also think you're overestimating the difficulty of selling two SLI capable cards. Look at how hard it was for people to get rid of GT's and Ultra's to step up to the 7800's.

But I'm really interested in seeing how ATi is going to handle all this.

 

[MrGuvernment]

Interesting proposition. Using the "Master" card as a leg-up for an upgrade does make sense. But you still have to consider the psychological impact of "knowing" one of your cards is running slower than it could even though you paid good money for it - I think that's going to be one of the biggest obstacles.

I also think you're overestimating the difficulty of selling two SLI capable cards. Look at how hard it was for people to get rid of GT's and Ultra's to step up to the 7800's.

But I'm really interested in seeing how ATi is going to handle all this.

Good point - i guess it would come down to ATI giving the ability to easy turn off one card if the single performance was well enough for X game na dif the 2 card would perform better then 2 are used.


For me aslong as i know and can see a performance increae over a single higher end card - i would be happy.

it will be nice once the product hits so we can see it effect and possibly what NVIDIA may have to counter it.


But if ATI's r520 is going to have 512bit ram on it - NVIDIA is in for a shit storm again.

 

[Terra]

But if ATI's r520 is going to have 512bit ram on it - NVIDIA is in for a shit storm again.

Why?

Terra...

 

[MrGuvernment]

256bit ram vs 512bit ram?


u seen comparisons on 128 vs 256

64 v 128 ?

there is a rather LARGE increase in performance, many think this is why 512mb of ram is almost useless because of the 256bit interface limiting it, but with 512bit ram things will fly


Of course we cant tell until ATi gets off their lazy asses and releases these carsd - if they ever do.

 

[kirbyrj]

Brent, any word on when these magical 80 series drivers will appear? Early/late September? Will there be performance improvements across the board or are we looking at mainly SLI compatibility and dual-core support?

"Mmm...Dual Core support" - Homer Simpson

 

[Brent_Justice]

512-bit memory bus is very unlikely

and speaking editorially IMO not needed at this point in time for games, games are more shader intensive than memory bandwidth intensive at this point, I'd opt for faster RAM at 256-bit

 

[Terra]

256bit ram vs 512bit ram?


u seen comparisons on 128 vs 256

64 v 128 ?

there is a rather LARGE increase in performance, many think this is why 512mb of ram is almost useless because of the 256bit interface limiting it, but with 512bit ram things will fly

What Brent said above

Terra...