[robmaister]

It's possible that it's an async compute task, which could potentially miss a frame and show old data (instead of the whole frame missing vsync).

Also this demo is supposed to be running on a PS5 devkit, which means that you'd need a devkit to run it, which means that you'd need to sign NDAs and join their developer programs and whatnot.

Having worked with current gen consoles (meaning I can't go into any amount of detail), it's not a trivial thing to get a demo like this running well on PCs. This demo is likely making use of every platform specific feature available to them.

That said, the demo might be accessible through some back channels if you're already a UE4 licensee and have a PS5 devkit.

[zamalek]

The link I shared wasn't UE5, and their other videos specifically indicate that they are running on PC - unbelievably modest PC hardware at that.

> it's not a trivial thing to get a demo like this running well on PCs

This old tired argument.

The current theory for how the meshing is done is something similar to mesh shaders (available on commodity PC hardware since 2018)[1]. This "PS5 platform specific feature" running on PC in 2018[2].

As for the lighting, NVDIA have already had this "platform specific feature" on PCs for some time now. It's called RTX. In 2018[3] (using DLSS), in 2020[4] (no apparent DLSS usage, but it may have improved).

Both next-gen consoles are essentially PCs. Their primary advantage is tightly coupled hardware (e.g. memory latency, the absurdly fast PS5 SSD). While dedicated raytracing silicon on AMD is currently unique to PS5 (AMD claims they can emulate DXRT on Navi), it has been around for more than a year in consumer hands in the form RTX.

[1]: https://devblogs.nvidia.com/introduction-turing-mesh-shaders... [2]: https://www.youtube.com/watch?v=CRfZYJ_sk5E [3]: https://www.youtube.com/watch?v=jkhBlmKtEAk [4]: https://www.youtube.com/watch?v=2744rWPvNuE

[robmaister]

I work in AAA. I'm talking lower level things like picking which "type" of GPU memory to allocate, access to specific registers in shaders, etc. PC didn't have real async compute capabilities until DX12, for example.

On the CPU side yeah it's 100% just a normal computer but nothing will be interrupting your threads. I think Windows 10 tries to do in it's new game mode too.

Sorry for assuming the link was the PS5 one. I have a UDN account and their login setup sometimes just dumps me to their homepage, so I made the assumption that it was the same video that I had seen everywhere else.

[zamalek]

> PC didn't have real async compute capabilities until DX12

Indeed it didn't, and DX12 is extremely old tech. Consoles don't have async compute right now. (Edit: apart from the PS3).

[robmaister]

AMD GCN absolutely supports async compute[1]. Radeon cards for years would only make use of the ACEs in pure compute contexts, as OpenGL and DX11 had no concept of a secondary command queue and could not make use of them. This is a big part of the reason why Vulkan/DX12 require so much boilerplate to get a triangle rendered.

The PS3's SPU definitely counts as async compute especially with how it was used later in the console lifecycle[2] once people had time to familiarize themselves with it.

However, in the current gen consoles, you don't have to deal with a different ISA, command queuing, and shared memory between the GPU and CELL processor. You are only writing HLSL/GLSL/PSSL and setting up an aggressive amount of fencing to transition resources between readable and writable states within the GPU.

[1]: https://www.anandtech.com/show/9124/amd-dives-deep-on-asynch... [2]: https://www.slideshare.net/DICEStudio/spubased-deferred-shad...