Not enough PCIe lanes available for multiple GPUs and PCIe NVMe drives.
Not enough PCIe lanes available for multiple GPUs and PCIe NVMe drives.
I operate this machine for video editing, AI-powered upscaling, and heating my home during winter. I'm considering an upgrade but want to verify the PCIe bandwidth availability. Many of my programs rely on several GPUs for rendering (such as Davinci Resolve), or I utilize one GPU for multitasking with Handbrake, Topaz Video AI, games, etc. My current configuration: i5 11600K, 64 GB DDR4 memory, Gigabyte B560 AORUS PRO AX ATX motherboard with 2 TB M.2-2280 SSDs and an RTX 3080ti GPU. I plan to install an RTX 3080ti with one NVMe drive, but expect to add more later. The existing 14900K supports up to 20 PCIe lanes, so how will performance change if all are utilized? What would happen with two GPUs and four NVMe drives?
16 lanes are assigned to the main PCIe port, four lanes connect to an M.2 slot, and the remaining slots pass through the chipset sharing the CPU-chipset bandwidth (PCie4 x8). The exact number of lanes per device varies based on the motherboard.
Ensure the board you purchase supports x8 x8 expansion in two PCIe slots and provides adequate spacing for two GPUs.
Only a handful of LGA1700 boards offer x8/x8 compatibility on the main CPU x16, though the ASRock Z790 Taichi appears to be an exception.
Precisely because the setup already provides sufficient capacity without requiring additional hardware.
The motherboard details suggest your bottom GPU is using the PCIe Gen 3.0 x1 port. Despite this, it continues to limit performance when paired with your 11600k CPU during heavy rendering tasks. Maybe the data transfer speed isn't the main issue here. Even though the slot was designed for higher speeds, it might still be constraining under certain workloads. Switching to a newer platform would likely provide better bandwidth capabilities.