this was also a reply on the listing on newegg aswell so this gives me hope
Confirmed Working on Legacy Bios Motherboard!1/12/2019 1:02:27 PM
Pros: This RX570 was plug and play for me. Confirmed working on legacy bios motherboard ASUS M4A87TD EVO with bios version 2001 dated 3/08/2011. OS: Windows 7 64 bit. I had problems with my HD5570 display drivers seemingly getting corrupted. No version I tried worked (I did use DDU as well) so I did some research and came across a little gem of information below (This may apply only to us Legacy Bios owners):
Some versions of Catalyst Control Center WOULD NOT update PCI Express drivers in windows/device manager. THIS caused no version of Catalyst I tried to work. In Device Manager, under System Devices there will be one of two entries. (3GIO) Filter or PCI Bus. 3GIO is the old one and needs to be updated to PCI Bus in order for newer versions of display drivers to work. I think this issue is why some people assume a newer generation of GPU will not work on legacy bios motherboards if the PCI Express driver is outdated? I'm not certain.
There is a guide online on how to update this but I think Newegg policy does not allow links. So I'll try and describe in short: Open properties on the system device in question (3GIO) filter if you have it, click update driver and browse to the folder where you downloaded your version of display drivers for your version of operating system. Let Windows update the driver. Once it is updated to PCI Bus restart your computer and than install your display drivers. I hope this helps some people out there!
Cons: None yet!