Per the datasheet, EPYC supports up to 128 PCIe lanes, does that mean that it can support up to 128 PCIe devices?
Every EPYC CPU has four dies, and every die includes two PCIe 3.0 x16 links. Each PCIe 3.0 x16 link can be bifurcated as you'd like for up to 8 PCIe device maximum per link. That means that each EPYC CPU can support up to 64 PCIe device in total.
Every EPYC CPU has four dies, and every die includes two PCIe 3.0 x16 links. Each PCIe 3.0 x16 link can be bifurcated as you'd like for up to 8 PCIe device maximum per link. That means that each EPYC CPU can support up to 64 PCIe device in total.