Could Nvidia make a raytracing only cards?

[RotoCoreOne]

Akin to dedicated physx cards of old? Pair it with your current gpu?

[emosun]

they could make anything if its theoretical. nvidia could make cupcakes if they wanted.

[vanished]

They could probably make it, but I don't think it would work very well.  I'm not sure what kind of communication goes on between the conventional GPU core and the AI cores and other new stuff they've added with the RTX cards, but I would suspect it is fast and numerous. If so, having that stuff on a separate card would completely cripple the performance and make it non-functional.  That said, even if it was physically possible I doubt they would go to the effort of offering such a tech.  It wouldn't make sense for them to allow people with AMD cards to use it, and as for their existing last-gen customers, it won't be long until everyone has bough a new card anyway.

[Syntaxvgm]

The computations would have to go to the main card before the frame could be rendered, and I'm sure that would introduce a few milliseconds of latency. I'm sure it could be done, but I doubt it would be perfect and the same card is a much better solution. 
The looking glass project
https://github.com/gnif/LookingGlass

copies from one gpu to the other gpu's framebuffer, and I think the resulting performance is something to go by. 
THAT SAID
That's a one way move, I'm sure data goes both ways to make a frame in the case of a separate card for ray tracing. 

[Spotty]

I very much doubt we will see dedicated raytracing cards. Such a card would still need to be basically an entire new GPU just without display outputs. Without knowing too much on how it works and what is required, it'll likely still need cuda cores as well as the raytracing tensor cores, plus lots of high speed vram. Then the cost of making the PCBs and coolers and whatever else. 

 

Would you pay $500 for a dedicated Ray tracing card that will only enable lighting effects and won't increase the rasterization performance/fps you get from your 2+ year old card?

 

Then there's also the complication of getting the older cards, that weren't designed with RT in mind, to communicate and work with the dedicated raytracing card. We've already seen nvidia move away from sli and towards nvlink on this new generation.

 

If you already have a high end 10 series GPU like a 1080ti, then just wait for the following gen of GPUs to upgrade by which time there will be a larger catalogue of games that support raytracing.

If you're the sort of person that has lots of disposable cash and wants the latest and greatest, then you're probably not going to want an add in card anyway and you'll just spend the $1200 on the 2080ti.

[kilgore_T]

mmmm NVidia cupcakes