If your x79 motherboard, i7 CPU and nvidia Geforce graphics cards all support PCIe 3.0 then shouldn't everything run at PCIe 3.0 speeds? The answer is no, by default your x79 motherboard and nvidia Geforce graphics cards will only run at PCIe 2.0 speeds which significantly hinders system and gaming performance. You have to Force Enable PCIe 3.0. By enabling PCIe 3.0 you will see a frame-rate increase of anywhere from 30-100 frames per second in-game. Lag and choppy game-play will be a thing of the past. This is especially important when running games on Ultra Settings with one of more monitors running at 1080p or higher resolutions. When running the Unigen Heaven 4.0 Benchmark on absolute max settings I was hitting an average frame-rate of about 80fps, after enabling PCIe 3.0 support my average FPS jumped to a whopping 123fps. In the Unigen Heaven Benchmark this kind of frame-rate jump is monstrous. Check out the tutorial steps below on specifically how to force enable PCIe gen3 on your system.
Video Tutorial
https://www.youtube.com/watch?v=gzGSqsidL30
Motherboard: ASUS ROG Rampage V Edition 10
CPU: Intel 6950x 4.2GHz
GPU: 2x Nvidia ASUS RTX 3090 with EK Water Blocks
Memory: Corsair Dominator Platinum 64GB (4x8GB) 3,600 MHz
M.2 SSD: Samsung 960 Pro NVMEI
Sound: Creative XFI Fatal1ty Champion Series
PSU: Corsair AX1200i