PCIe 4 and PCIe 3 specifications
PCIe 4 and PCIe 3 specifications
The difference in performance between a 6700XT using PCIe 4x16 versus PCIe 3x16 slots would be notable.
Under simple conditions, PCIe 3 and PCIe 4 will deliver almost the same results for the RX 6700 XT. However, on boards with both Gen 4 and Gen 3 x16 ports, the Gen 3 slot rarely supports full x16 bandwidth—typically capping at around four lanes, while Gen 3x4 PCIe lanes will show a noticeable performance gap compared to Gen 3 x16 or Gen 4 x16 configurations.
Based on the extent of damage, the PCIe 4.0 port should still work well, even if the locking mechanism is faulty.
If it's only the locking tab, simply insert the GPU into the slot. The screws secure it in position; the locking tab is mainly there for transport purposes.
On B660 motherboards, the PCI-E 3.0 X16 port is usually not operating at full speed electrically—it appears as X16 physically but works at X4. This can limit the GPU's bandwidth. If the locking tab is damaged or absent, the port should still function properly. The back mounting screws can provide additional stability. Results vary based on the extent of the PCI-E 4.0 X16 slot damage.