Clarification on GPU bandwidth in relation to PCI Express slots

Link Width x8 vs x16??? gpu slot width Cards larger than 60mm puts clearance between the glass and GPU fans around ~15mm or less and could put your card at risk of overheating despite having gpu slot GPU Chipset Manufacturer Memory Size Cooler Max GPU Length Form Factor Interface Memory Interface DisplayPort HDMI Slot Width Single Slot

gpu with m2 slot Width: cm ; Depth: cm ; Weight : kg ( M3 Pro with 12-core CPU, 18-core GPU and 16-core Neural Engine; M3 Max