PCIe 5.0 supports multiple lanes and higher bandwidth capabilities.
PCIe 5.0 supports multiple lanes and higher bandwidth capabilities.
You're starting out with a new gaming setup using the ASUS ROG Strix Z690-E MB. Your main concern is how bandwidth works in the PCIe slots, especially with your EVGA RTX 3090 and the M.2 slots. The manual mentions that when an NVME SSD is placed in the M.2_1 slot (which also supports 5.0x speed), the GPU slot will operate at a higher rate—specifically 8x speed. This suggests the PCIe lane is shared or prioritized, potentially boosting performance.
Your question is whether this means your GPU will run at 4.0x8 or 5.0x8 speed. Since the card supports both 4.0 and 5.0 lanes, it's likely optimized for the higher bandwidth option. However, most modern GPUs are designed to handle up to 4.0x16 bandwidth, so 5.0x8 is still substantial. The concern about current GPUs not reaching that speed is valid, but your setup should benefit from the available lanes.
Regarding future plans, using two NVME SSDs and anticipating M.2_1 slots for 5.0 devices shows thoughtful planning. If your GPU maintains its performance, you won't lose much efficiency. Just keep an eye on any updates or changes in PCIe standards.
Your question is clear—thank you for clarifying the details!
The initial card supports PCIe 4.0, which means it won't use 5.0 signaling, resulting in a 4.0 x8 configuration. This shouldn't be an issue for a premium device.
It should operate at 4.0x8, matching the bandwidth of 3.0x16. Running similar to CS:GO at 1080p with top-tier CPU would result in a loss of about 1-3% performance because of the PCIe limitation. Various tasks might experience greater drops, but for gaming it remains negligible.
Thank you all for your prompt replies. The chart supported my earlier belief—that even at 4.0x8 there’s no noticeable drop in performance, at least currently. With PCIe 5.0 NVMe SSDs arriving soon, I’ll be able to fully utilize that bandwidth. Perhaps when the RTX 5000 line is released, we should reassess this, but that’s still some time away. I relied on experts to provide clear guidance. As someone who enjoys tinkering with computers, it’s rewarding to help others, especially when friends are willing to assist.