Say NO to the Paywall of PCI-E Bifurcation — Gray's grind

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2024-09-19 19:00:04

PCI-E provides CPUs the ability to connect with fast devices, like >10 Gbps networks, NVMe SSD, etc. Especially for the usage of workstations or servers, the number PCI-E slots means a lot. As a result, Xeon CPUs and server-level MBs provide more PCI-E slots than on the consumer level. On the other hand, the number of PCI-E slots on cheap MB is usually only 1 for GPU. However, those server-level MBs are more expensive.

PCI-E bifurcation is a method of dividing x16 PCI-E channels into various combinations, such as 8+8 or 8+4+4. This approach is useful for devices that only support x4 or x8 speeds. However, unlike AMD, Intel’s consumer-level motherboards seldom provide this option in the BIOS, especially on lower-end products.

Let’s do some hacking to bypass such paywall. My platform is Intel Core i5-3450 + Z77, but I guess this method is also useful for any Intel CPU with public datasheet information, like 12th gen CPU[3].

First, go to the Intel ark document webpage to check the “PCI Express Configurations”, which will show all bifurcation modes that your CPU supports.