[maccard]

I agree with you in theory. A couple of points - that’s currently the most experience and high performing card on the market. Most people on steam are using an RTX 3060 which has more like 360GB/s. That’s a factor of 6. How do you design resource usage that scales with that amount of extremity? (We try to, fwiw).

That spec is also a throughput measured per second whereas our frame rates are much higher than 1/s. At 60hz, that’s now between 140 and 800 textures a frame. If you miss _one_ you don’t get that back.

A single main character in a game can be 2-5 regular textures, plus all of the extra mapping textures we have these days. Now do landscapes, environments, props, background videos, and it all adds up. 4k textures are pretty universally used. If you look at a tiny object up close we need a higher res texture to be able to show it neatly.

You also have memory pressure - raytracing makes heavy use of VRAM so you have to make the tradeoff of how much do you want to allocate to caching lighting, vs how much you want to keep textures and geo around.

Lastly, as you say, actually keeping up with 360GB/s from the CPU side is tough. If you require any transformation or CPU operations that’s just not going to happen. If you need to pull from disk, even on an NVMe drive reading synchronously, the max throughput is < 10% of that, and that assumes you are actually reading 360GB from disk. If you pause to do anything else, you’ll significantly slow that down. Players also generally don’t like it if we thrash their NVMe disks :)

[nearbuy]

All good points.

Absolutely an RTX 3060 is a more normal gamer GPU than the 5090, but you're also not playing in 4k without DLSS on a 3060. Drop to the most common resolution on Steam (1080p), and turn on DLSS and you've basically cancelled out that 6x factor in bandwidth. Even if the 3060 had more bandwidth, it doesn't have enough processing power for native 4k gaming in typical games. So 360 GB/s is still a lot of bandwidth for the resolution most 3060 gamers are using.

[maccard]

Playing at 1080p doesn’t reduce your texture size, for the most part. You still use those 4k textures because you’re only seeing a subset of the texture projected at a close distance. We’re still using 4k textures for terrain brushes to cover the 6km open worlds.

DLSS isn’t just a magic on switch for free perfect up scaling. If you rendered at 720p and DLSS’ed up to 1080 it’s still going to look pretty rubbish.Its always surprising to me just how many people have 1080 monitors though given we’ve had more than that for two generations of consoles.

And lastly - all the same points still apply about frame rate (which can be more than 60) and memory bandwidth per frame and cache invalidation etc at 360GB/S, as they do at 1.8TB/s

[nearbuy]

> Playing at 1080p doesn’t reduce your texture size, for the most part. You still use those 4k textures because you’re only seeing a subset of the texture projected at a close distance.

That greatly reduces your GPU memory bandwidth though. Sampling a subset of the texture only transfers that subset. Reading from higher mip levels uses less bandwidth. If your textures are high enough resolution to appear sharp at both resolutions (at least one texel per pixel), you need 4x more bandwidth to sample your material textures at 4k screen resolution for the same scene.

More importantly, material texture sampling is not most of your bandwidth to begin with. At 4k, most of your bandwidth is going to your full screen render passes. Especially with deferred rendering.

> DLSS isn’t just a magic on switch for free perfect up scaling. If you rendered at 720p and DLSS’ed up to 1080 it’s still going to look pretty rubbish.

I don't find this true at all. DLSS 4 Balanced looks excellent and renders at less than 720p for 1080p output.