Saturating 16 lanes is very doable, although for a very short amount of time. You'll never see it last more than half a second at absolute worst on normal usage

Saturating 16 lanes is very doable, although for a very short amount of time. You'll never see it last more than half a second at absolute worst on normal usage, maybe more if you're trying to upload on a 192GB GPU or something. But since most uses evict data out of GPU RAM before writing instead of blindly overwriting, it's not a problem you could ever reasonably have.