Gigabyte Enables PCIe 4.0 Option In X470 BIOS Update

Credit: Tom's HardwareCredit: Tom's Hardware

Over the last few weeks, motherboard makers have released a steady stream of BIOS updates to support AMD's Ryzen 3000 processors, but Gigabyte's newest BIOS has a special feature: The company has enabled the option for PCIe 4.0 in the BIOS of its X470 Aorus Gaming Wi-Fi 7 motherboard. That signals that, under some circumstances, the company will likely support PCIe 4.0 on existing motherboards if you drop in a new Ryzen 3000 processor.

An alert redditor noticed the new setting in Gigabyte's F40 BIOS, and our motherboard team verified that this option now appears in the Gigabyte BIOS under the PCIe Slot Configuration submenu. f40 BIOS - Credit: Tom's Hardwaref40 BIOS - Credit: Tom's HardwareF3c BIOS - Credit: Tom's HardwareF3c BIOS - Credit: Tom's Hardware

Our team also verified the setting isn't available with the previous F3c revision of the BIOS.

Gigabyte hasn't officially announced PCIe 4.0 support for its 300- and 400-Series motherboards, so it is unclear which models would support the faster interface, or if there will be limitations on some motherboards. It should go without saying, but you would also need a processor that supports PCIe 4.0 to utilize the faster transfer speeds, so current-gen Ryzen CPUs will still operate at PCIe 3.0 speeds.

AMD will also support PCIe 4.0 with its next-gen 500-series motherboards, ushering in a new wave of powerful devices like faster SSDs, but as part of AMD's standard promise of backward compatibility for AM4-Socket processors, these new 7nm processors will also drop into the existing X370, X470, B350 and B450 motherboards that are already on the market. (Support for A-series motherboards is still curiously up in the air).

We've known for some time that, under some conditions, existing PCIe 3.0 motherboards can support the faster signaling rates of the PCIe 4.0 specification, but AMD's motherboard partners have not explicitly announced that the feature would come to existing models.

At CES 2019, AMD confirmed to Tom's Hardware that 300- and 400-series AM4 motherboards could support PCIe 4.0. AMD will not lock the out feature; instead, it will be up to motherboard vendors to validate and qualify the faster standard on their motherboards on a case-by-case basis. Motherboard vendors that do support the feature will enable it through BIOS updates, but those updates will come at the discretion of the vendor. AMD also cautioned that most motherboard vendors might not bother supporting the faster interface on existing motherboards.

In either case, on existing motherboards, support could be limited to certain slots based upon board, switch, and mux layouts, and any trace routing on the motherboard that exceeds six inches would require newer redrivers and retimers that support PCIe 4.0's faster signaling rates. That means some older motherboards could supply a PCIe 4.0 x16 connection to the first slot on the motherboard, but the remainder of the slots would revert to PCIe 3.0 signaling rates. Any PCIe slots with an attached PCIe 3.0 switch would also be excluded from supporting the faster speeds, so some of the fancier motherboards with elaborate PCIe routing setups will not be eligible. All PCIe lanes that hang off the PCH will also remain at PCIe 3.0 speeds.

That means that we might see some complicated support matrixes appear to outline which previous-gen AM4 motherboards, and which slots, will support PCIe 4.0 when used in conjunction with a Ryzen 3000-Series processor.

But the larger story is that it appears support will come in some fashion, which is quite the bonus upgrade path for enthusiasts with Ryzen-powered systems. Meanwhile, we aren't sure of a firm arrival date for PCIe 4.0 for Intel's chips, and given the chipmaker's proclivity for frequently introducing new sockets, that support likely won't come to existing motherboards.

We've pinged Gigabyte for more details and will update as we learn more.


11 comments
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  • remixislandmusic
    I hope this doesn't mean there is an issue with X570. Doubtful tho since they are going to announce soon.
    I actually think we will benefit from PCI-E 4.0 later on, however, most current devices won't benefit from it. I do think this slightly adds to Ryzens ever strong value since you can buy a potentially cheaper X470 board and get Ryzen 3000 support and PCI-E 4.0.
  • razor512
    I wish they would make the mainstream CPUs offer more PCI express lanes. What is sad is that they are providing boards with multiple m.2slots but all of them require some compromise to use.

    Soma boards will take a few lanes from the CPU, thus forcing your video card to run at X8 speed, while others may run off of the chipset, but share the equivalent of an X4 link with the X1 slots, as well as the sound card, USB ports, Ethernet ports, and SATA ports, thus any activity on any of those devices, directly reduces the throughput of your NVMe SSD (e.g., if you have a 970 pro, and play an mp3 from a different drive, you will notice that the soundcard will directly lower the throughput. same with the Ethernet port, or a SATA port.

    With that in mind, they need to start offering at least 24 PCI express lanes so that a basic setup of a decent NVMe SSD, a few hard drives on the SATA ports, a PCI-E GPU, and probably 1 or 2 PCI-E X1 devices, all without having to deal with performance being crippled.
  • hannibal
    The price, the price and segmentation. More lines means more complex motherboard. Also They make pro models more appealing because those offers more lines and They can ask more money from pro models. Same as with normal vs professional GPUs.