In a rather surprising move, ASUS has enabled support for the 1st Gen AMD Ryzen CPUs (Summit Ridge) and APUs (Raven-2) on its ROG Strix X570 motherboards. This essentially means that the Strix X570 platform may support all four generations of AMD CPUs and APUs (at present three) at a time. Pretty freaking impressive. AMD officially doesn’t support the 1st and 2nd Gen Ryzen CPUs on the X570 boards. Only the 3rd Gen and the upcoming 4th Gen Zen 3 based chips will be (officially) supported on the X570 platform.
A while back AMD decided to retain support for the 4th Gen Ryzen CPUs on the B450 and X470 boards after widespread community uproar. The reason why Team Red decided to drop it in the first place is that the older boards come with a 16MB ROM chip which can’t hold compatibility data for all three generations, along with the advanced I/O features and UEFI BIOS. All newer chipsets including the X570 and B550 come with 32MB BIOS ROM chips (sometimes even two of them) to allow for extended processor compatibility.
The ASUS ROG X570 Strix also features a 256Mb (32MB) BIOS chip which allows it to retain support for all three generations of Ryzen processors, plus the APUs. It’s not 100% certain whether support for the 1st and 2nd Gen Ryzen chips will be retained when the 4th Gen lineup lands, as there might not be enough space for four CPU and three APU generations (plus the PRO variants) on a single BIOS ROM chip. There’s a good chance that at least the APUs’ will be dropped as their support data takes more space than that of regular CPUs.