No, it won't be limited by PCIe 4.0 with 16 lanes.
No, it won't be limited by PCIe 4.0 with 16 lanes.
Your current setup seems fine for the RTX 5080. The B650-Plus supports PCIe 4.0, so no immediate bottleneck concerns. You’re probably overthinking it—upgrading now isn’t necessary unless you want extra flexibility.
Testing PCIe scaling with the 5090 revealed noticeable bus usage peaks during gaming sessions—something I hadn’t observed before. The impact on performance remains small compared to newer generations, though. I’ve been keeping an eye on my 5070 Ti since installation. Occasionally, during games, the bus utilization reaches its maximum, which hasn’t happened with previous models. Further investigation is needed. It doesn’t seem to hinder regular gameplay, but it could slightly influence loading times.
It depends on your CPU model, not just the number of lanes. Since 2008, the PCI-e slot supporting x16 has been standard, even in older chips like Kaby Lake or earlier. This doesn’t apply here. What matters is the actual performance of your CPU, its generation, and the components involved. Usually, you should avoid using mobile CPUs via adapters. Opt for high-quality CPUs available at the time the GPU was installed—they’re built for power efficiency and match the optimized drivers for your CPU type. Even with a 16-bit PCI-e slot, both older and modern CPUs can become bottlenecks if paired with less capable GPUs. Most systems now have a dedicated x16 slot, so it’s not a problem unless you're using budget mini-ATX boards.
I asked the identical question someone shared earlier, but I didn’t choose to upgrade my 4080 with a 5080. The 3-7 FPS boost didn’t justify the cost for my needs, and I’m not concerned about the fake frames. Meanwhile, GN conducted a fresh test on the 50 series—perhaps you’d find it useful?