Seems like Asrock's mobos don't support Picasso, but...
AMD Ryzen series CPUs (Matisse)
- 2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3: Gen3 x4 mode)*
AMD Ryzen series APUs (Renoir)
- 2 x PCI Express x16 Slots (PCIE1: Gen3x16 mode; PCIE3: Gen3 x4 mode)*
AMD Ryzen series CPUs (Matisse)
- 2 x PCI Express x16 Slots (PCIE1: Gen4x16 mode; PCIE3: Gen3 x4 mode)*
AMD Ryzen series APUs (Renoir)
- 2 x PCI Express x16 Slots (PCIE1: Gen3x16 mode; PCIE3: Gen3 x4 mode)*