PCIe x8 NIC in PCIe x16 slot

13, Intel X299, 8 x DDR4 DDR4 4200+, 4 x PCIe x16 1 x , AMD 3-Way CrossFireX NVIDIA 3-Way SLI, na, CH HD , GLAN + Wi-Fi, 0,

The specs state that the PCIEX4 and PCI Express x1 slots conform to PCI Express standard In which PCIe slot did you drop the to PCIe x4

4x4bet slot PCI-e slot on your motherboard and these only run at 8x or even 4x speeds, they will still work, but performance can be lower than in a full speed slot

4x4 turbo slot Marvell 88SE9215 PCIE to SATA Card PCI-E Adapter PCI Express to Expansion Card 4Port SATA III 6G for SSD HDD IPFS Mining · TISHRIC PCIE SATA 4X 1X