Item — HN Reader

If VRAM is low, data traffic between system memory and GPU VRAM increases greatly, and the PCIe link can become the bottleneck, especially if the GPU runs at x8. In extreme cases, performance may drop to ~ one eighth. ( 24.6 FPS -> 3.3 FPS )

  "Dragon Age: The Veilguard" - 2560 x 1440:
  - RTX 5060 Ti 8 GB on PCIe 5.0: 24.6 FPS
  - RTX 5060 Ti 8 GB on PCIe 4.0:  3.3 FPS   !!!!

https://www.computerbase.de/artikel/grafikkarten/nvidia-gefo...

2 comments

The irony is that it's the budget cards which have fewer PCIe links. That RTX 5060 Ti 8GB only has 8 lanes, but could really benefit from having 16 lanes. An RTX 5090 with 32GB of VRAM? It has 16 lanes, but would do just fine with 8...

That has to be a bug.

More likely, just lazy optimisation.

From earlier in the article they say this testing is with ultra settings, and for a modern game it would be expected that they're creating content that shows off well at 4k resolution and easily push past what 8GB VRAM can contain. The PCIe5 system is still affected, it's just affected less. There's probably tricks they can use to stream detail levels in/out of VRAM depending on how objects are displayed on screen (like the early direct storage+sampler feedback demos), but that's more work to do effectively and would still put pressure on PCIe and storage being fast enough to keep up.

I'd say it comes down to players picking appropriate settings for their system, and it being good if the developer can can provide the information on the consequences of different settings (showing VRAM usage), or a warning if you're below their required/recommended system.