RTX on GTX cards

Hey everyone.
So I saw some articles online, stating that NVIDIA will be bringing raytracing to some GTX cards. Obviously, it will run slower than on RTX, but does anyone know if that means that Unreal will also support RTX on GTX cards? It will be SO useful for people like me, who use Unreal mostly for rendering short-films/animations and not real-time games.

As far as I’ve seen, there hasn’t been any official information from Epic. So far it’s exclusive to RTX cards.

Once Nvidia updates the drivers I don’t see why it wouldn’t work automatically in UE4

That’s what I’m thinking. Apparently the drivers work in such a way that game developers won’t have to change a thing for it to work

That’s what I’m thinking. Apparently the drivers work in such a way that game developers won’t have to change a thing for it to work in games.
That said, it’s meant to work that way in shipped games, I have no idea how it applies to Unreal Engine itself :\

Unreal Engine does not contain any RTX-specific code. Our ray tracing implementation is working on top of DirectX Raytracing API (DXR), which is hardware-agnostic.

When we launch the engine in -dx12 mode with ray tracing enabled for the project, we always attempt to initialize the DXR back-end (we ask the API if it’s supported on the current system). So if any hardware vendor releases a driver that implements DXR, things will just work with no code changes on the engine side (other than any bugfixes that may be required when running on hardware that was previously untested).

Well, that’s great news for all of us GTX users! :slight_smile:

I’ve read that raytracing support on GTX cards will not be of the same quality - casting less rays than their dedicated raytracing RTX counterparts. Like Shain98, we hope that raytracing with Unreal Studio will help us to create faster renderings and animated frames for films - without having to rely so much on the baking process.

when nvidia will release april driver :mad::mad:

As far as I believe, you can set the number of rays yourself in UE, just like in an actual raytracer, say V-Ray or Arnold.
I think they meant it will shoot less rays in the same time as it cannot compute them as fast. So if someone wants to play actual games with RTX on a GTX then he will have to set the raytracing quality lower to have a playable framerate. At least that’s how I understand it.

And now to wait for the driver to be released…

I don’t have an RTX card but will it be possible to take advantage of the coming driver update for GTX to make very high quality cinematic videos at least?

The sequencer could really do with a ultra high quality and ray tracing output mode including audio plus actually render to mp4.

I would imagine that even on the non-RTX cards there will be a huge speed advantage using it for videos and images.

With a really high number of rays on the path tracer sequencer could output stuff close to offline renderers.

The path tracer is unbiased so it’ll be much slower than the realtime raytracing but the results should be similar to VrayRT or iRay

Is there any required mechanic to how a DXR-eligible card has to be situated on the running PC?

Can UE4 utilize more than 1 DXR card as multi-GPU rig (Like the traditional VRay, Iray, or Octane Render on Maya, C4D, or 3DS Max)?

Does the card have to be situated as the main motherboard card, or can it be a 2nd or 3rd card, where the main mobo GPU was say a Maxwell card (non-DXR)?


For now UE4 is not working with multi-GPU but the feature is on roadmap (confirmed at GDC 2019 and at Livestream after it), but there is no ETA yet.

There have been reports that more than one card on the system (both RTX) were not working properly and users had to remove one of them. After 4.22 release I didn’t catch any report, but Epic staff might have been receiving them, so if I was you I would test and in case of trouble or crash fill a Bug submission report, because the simple presence of a 2nd card should not cause issues.

The PCIe slots available at your motherboard have difference in the bandwidth they can provide. Usually the slot closest to the CPU socket is x16 and the second is x8, but that might change depending on your system, ie your motherboard and processor support Threadripper, each PCIe slot will be x16, so order would not be important. In case of Intel and AMD desktop CPUs (except threadripper) the graphics card more capable should always be the one at the PCIe closest to the CPU socket, this way you can have the full bandwidth at the cards disposal, otherwise you are wasting a card elsewhere.

Good info, thank you!

when they will release april driver :mad::mad::mad::mad::mad::mad::mad::mad:

They have done so, be happy !!!

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