News Supermicro Joins Z490 Party With PLX Chip, Four PCIe 3.0 Slots

"However, PLX chips have become quite expensive in recent years, so don't expect this board to come cheap."
Nice understatement there!
3.0x16 in to 4x3.0x16 out is 80 lanes, which would require something like a PEX8780 and cost a cool ~$300 on its own or ~$450 for its PEX9781 refresh.
 
"However, PLX chips have become quite expensive in recent years, so don't expect this board to come cheap."
Nice understatement there!
3.0x16 in to 4x3.0x16 out is 80 lanes, which would require something like a PEX8780 and cost a cool ~$300 on its own or ~$450 for its PEX9781 refresh.

not really , this motherboard works 16/null/16/null OR 8/8/8/8

This is the cheaper PLX 16x to 16x/16x OR 8/8/8/8