Not an expert, but at least on the gaming side of GPUs my understanding is that you usually aren't using the bandwidth much. For rendering your average frame, a

Not an expert, but at least on the gaming side of GPUs my understanding is that you usually aren't using the bandwidth much. For rendering your average frame, all the data you need is already in VRAM. But if there's new model or textures that aren't yet on the GPU, you want to move them over quickly because the next frame needs to go out ASAP. For a game running at 60hz you've got 16ms to avoid a frame delay. At 144hz you have 7ms. So it can be helpful to be able to dump stuff to VRAM very quickly, which the GPU can grab from system memory via DMA at very high speeds. For most model/texture loading you know an object is coming into the scene and would have put it on the GPU ahead of time, so this a sort of worst case scenario shouldn't really come up unless you have a huge number of possible things that could spawn in and you don't know which until the last minute. Pretty unlikely. For the biggest transfers, like loading in an entire level worth of assets, you can hide it with loading screens, or load low resolution textures to start with and stream in the high resolution versions to catch up. Having more PCIe bandwidth will help speed that up if it's in system RAM, but if you're loading it all from disk that's going to be your limiting factor. I saw some benchmarks years ago where running a high end GPU at x8 or even x4 had pretty minimal impact. With high res textures coming in for 4K now I'd be curious to see someone run that again. Realistically, I don't think gamers should care about it beyond the spec one-upmanship. HPC would get a lot more use out of it. Maybe also a shift toward fast PCIe based storage solutions like Intel's Optane?