ASUS B250 Mining Board - PCI Express Lanes - CPU support

[martinsky]

I'm shopping around for a low power CPU (35W) for my B250 mining board, and noticed that several of the officially supported CPU's only support 16 x PCI Express Lanes.  Now given the board has 18 x PCIe 1 and 1 x PCIe 16 slots, it would seem that the CPU would need to support more than 16 x PCI express lanes.  Or is that not really the case?

But if that is the case why does ASUS list several supported CPUs (e.g. Celeron G3930T, Core i3-6100T, Core i3-7100T) that only support 16 x PCI Express Lanes?

https://www.asus.com/us/Motherboards/B250-MINING-EXPERT/HelpDesk_CPU/

[Vann]

The B250 chipset supports 12 native PCI-E lanes. The rest are through a PCI-E expansion chip. Just because the motherboard will theoretically work with a cheap CPU dosen't mean it's the best option. If you plan to run Windows, I would definetly go with a Core i3 for a 12+ GPU rig. A better processor makes the setup, driver installation much faster, the system more responsive and IMO, is worth the extra $60-$80 compared to a bottom of the barrel Celeron which will struggle just to even run Windows 10, much less with 12 or more GPU's.