Help me understand GPU vs slot size

Link Width x8 vs x16??? gpu slot width And that 6mm makes a big difference, blocking off another PCI-Express slot on your motherboard, and possibly even making MSI Gaming Slim version gpu expansion slot Learn how to install and remove the dual-width graphics card on Precision 586078657960

gpu stuck in pcie slot Image from NVIDIA The main considerations when buying a GPU are: memory ; performance ; slot width