These ASUS X470 and B450 boards support PCIe 4.0!
There has been rumors of AMD X470 and B450 boards supporting PCIe 4.0. And certain manufacturers actually released BIOSes for the older boards, adding support for the faster interface on them. But then AMD themselves explained that they won’t be enabling PCIe 4.0 officially on the older boards, citing questionable reliability and the more stringent requirements that PCIe 4.0 imposes upon the motherboards. But, if you still want to, you can.
ASUS has apparently published a list of their boards, some of which support PCIe 4.0 on their primary M.2 SSD slots, while some even supporting the full set: PCIe 4.0 x16 on the primary PCIe slot and PCIe 4.0 x4 for SSDs. For most users at this point in time, the latter is of more value, because GPUs are far from being bottlenecked by the PCIe 3.0 x16 interface. Not to mention the only consumer GPUs supporting PCIe 4.0 are the AMD Radeon RX 5700 XT and AMD Radeon RX 5700, which are mid-range cards.
So here’s the full list of ASUS’ X470 and B450 motherboards supporting PCIe 4.0, as well as the BIOSes you need to enable the support:
ASUS PCIe 4.0 support
|Chipset||Motherboard||BIOS||PCIe x16_1 slot||M.2_1 slot|
|X470||ROG Crosshair VII Hero (WiFi)||2406||No||PCIe 4.0 x4|
|ROG Crosshair VII Hero||2406||No||PCIe 4.0 x4|
|ROG Strix X470-I Gaming||2406||No||PCIe 4.0 x4|
|ROG Strix X470-F Gaming||5007||PCIe 4.0 x8||PCIe 4.0 x4|
|Prime X470-Pro||5007||PCIe 4.0 x8||PCIe 4.0 x4|
|TUF X470-Plus Gaming||5007||PCIe 4.0 x16||No|
|B450||ROG Strix B450-E Gaming||2406||No||PCIe 4.0 x4|
|ROG Strix B450-F Gaming||2406||No||PCIe 4.0 x4|
|ROG Strix B450-I Gaming||2406||No||PCIe 4.0 x4|
|TUF Gaming B450M-Plus||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|TUF Gaming B450M-Pro||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|TUF Gaming B450-Pro||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|TUF Gaming B450-Plus||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|Prime B450M-A||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|Prime B450M-K||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|B450M-Dragon||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|B450M-D3V||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|Prime B450-Plus||1607||PCIe 4.0 x16||PCIe 4.0 x4|
|Prime B450M-Gaming/BR||1607||PCIe 4.0 x16||PCIe 4.0 x4|
For some reason, ASUS’ more affordable B450 boards offer better support for the PCIe 4.0 standard than even their flagship ROG Crosshair VII Hero. Do note that ASUS won’t be able to continue supporting these features in upcoming BIOS versions since AMD has already issued the directive to not support PCIe 4.0 on older platforms. When AMD releases newer AGESA updates to improve performance on the 3rd Generation AMD Ryzen processors, you will have to choose whether PCIe 4.0 is more important to you, or better CPU performance.
Meanwhile, here’s a tempting screenshot of a PCIe 4.0 SSD running at 5GB/s on a TUF Gaming B450M-Pro.
For the less ambitious of y’all, ASUS has also released BIOS updates to the X370 and B350 boards to support the AMD Ryzen 3000 series CPUs. No PCIe 4.0 support, but not every vendor is supporting the latest CPUs on the aging platforms, which celebrated its 2nd birthday back in March. If you own any of the older ASUS boards, you are in luck. The 3rd Generation AMD Ryzen processors are just a drop in upgrade for you.
Pokdepinion: I was planning on getting the ROG Crosshair VII Hero with my Ryzen 7 3700X… I guess I have every reason to do so now!