Why not just have an RT render card as an add-on?

[Donnie Fisher]

I can’t help but think that a lot of gpu die space has been given over to an as yet unused feature in graphics which for a lot of the time may be going unused in general.

Why not have the RT cores on a separate PCIe card to the GPU so that if you wanted rt compute, you use that, leaving the gpu cards more space to improve over previous gen.

The quadro announce discussed how 2 cards could be paired to share resource which implies the data can be passed between card in the necessary timeframes. so surely that idea could be the means to add rt to gpu separately?

 

[Undesirable]

Because that would give us too many options as consumers when it would be more profitable not to. If people don't have to buy it or have it forcibly thrust in their face (double entendre intended) then it can fail. See PhysX. Well, technically that's a poor example because we don't see it used in any games nowadays, but you know what I'm saying; Ageia failed whilst it was a simple add-in card, NVIDIA acquired the tech and it was forced upon us on board GPUs and undoubtedly sold them a lot more cards and increased their mindshare at the time. If the PhysX card was still sold separately, people could have opted not to buy it then expected the GPUs to be cheaper as they didn't have it built in, and so on and so forth.

Let's not forget the debacle of PhysX enabled games that performed worse on AMD cards even with PhysX turned off. Time will tell if something similar starts happening with RTX enabled games.

 

[Gerard]

In the long run if they were to adopt a second card it would give developers even more (valid) excuses not to implement Ray Tracing. They would have to set the game up to be illuminated in the standard method, then go through that all again with the RT option. Bound to cause issues with performance bottlenecks and bugs arising from 2 lighting methods. It would either be regular lighting or RT, and since RT would be the addon card that is bound to have a smaller user base it would be regular lighting all the way.


AMD are also bound to have this an an option at some point as well and no doubt the 2 iterations will have different implementations and have to be coded for separately, which is another reason devs are likely to give the middle finger to this, at least for the foreseeable future.

 

[dreigns]

There are a few reasons

1 - To set it as a new standard and if AMD can get it working well as well then its all good for the future and a new way to bechmark cards.

2 - From what they said last night while the engineering isn't easy in games its still over all less work then what they have been doing ( this is what I toke from the show ) and looks better as well.

3 - If it was a add-in card no one would buy it really just as with the Physx add-in card from year ago before nvidia bought the company

 

[Donnie Fisher]

All fair enough points. Cheers.

 

[ubersonic]

it would give developers even more (valid) excuses not to implement Ray Tracing. They would have to set the game up to be illuminated in the standard method, then go through that all again with the RT option.

Pretty sure that's how games are going to be set up for the next decade anyway. Just like the transitions from software to hardware rendering, T&L, Vertex shaders to Lightmap, various versions of Direct3D (with some games supporting four or five D3D versions plus OpenGL).

To set it as a new standard and if AMD can get it working well as well then its all good for the future and a new way to bechmark cards.

IIRC AMD already have it working, they just aren't pushing the tech before the GPU power is there.

The Radeon Rays tech is already working in the Unity engine, where Vega showed substantial improvements over CPUs.

 

[Nutella33]

The Radeon Rays tech is already working in the Unity engine, where Vega showed substantial improvements over CPUs.

They offer it for workstations already I think as well, limited/in production release so far tho. Its on their GPUOpen Initiative

https://gpuopen.com/announcing-real-time-ray-tracing/