cageymaru

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Gigabyte has released its new F40 bios for the X370 K7 that enables PCIe Gen 4.0. Other boards should receive similar support soon. It is very important that you follow the instructions for upgrading the bios. I did this with a USB stick and directly within the bios. First you need to install EC FW Update Tool (B19.0517.1 or later version) to avoid 4DIMM DDR compatibility on 3rd Gen AMD Ryzen CPU. This is found within the Utility section of your Gigabyte motherboard's support page.

This will reset your bios version to F2 after rebooting if I remember right. It is okay and don't freak out! Next you need to update to bios version F31 from the link above. Then you can subsequently update to bios version F40. Thus you need to have both bios versions unzipped on the USB stick.

Robert Hallock from AMD said this about older motherboards getting upgrades to PCIe 4.0. AMD doesn't officially support it. Free is free so YMMV.

At any rate you're going to want to upgrade the bios for 3rd gen Ryzen processors. It does get rid of support for Bristol Ridge processors as the physical space on the bios is too small to support everything.

Stay [H]ard and [H]ave fun!
 
What does this mean?
Clueless like you. I copied it verbatim from the link to the F40 bios. :)

F40
10.17 MB
2019/06/14

Update AGESA 1.0.0.2 for 3rd Gen AMD Ryzen™ CPU full support
Note:
1. If you are using Q-Flash Utility to update BIOS, make sure you have updated BIOS to F31 before F40.
2. Before update BIOS to F40, you have to install EC FW Update Tool (B19.0517.1 or later version) to avoid 4DIMM DDR compatibility on 3rd Gen AMD Ryzen™ CPU.
3. Due to BIOS ROM size limited, no Bristol Ridge APU support.
 
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A bios update cannot enable PCIe Gen 4, unless the board and processor already support it in hardware. Since out X370 boards do not support PCIe gen 4, it is not physically possible to enable it.
 
A bios update cannot enable PCIe Gen 4, unless the board and processor already support it in hardware. Since out X370 boards do not support PCIe gen 4, it is not physically possible to enable it.

I honestly am not certain:

Either

The PCI controller is on the CPU itself, and the motherboard just exposes the interface and divides lanes; in which case, with the proper CPU, an older motherboard could in fact support PCI 4.0

or

The PCI controller is implemented, either in whole or some fraction, on the chipset. In which case, you would be correct, the hardware on the motherboard would need to be updated alongside the BIOS.

My understanding is that current AM4, the CPU provides some PCI support, and that is just passed through. The chipset then provides additional support (usually just some additional PCI 2.0 from what I can gather on existing boards)... so the PCI lanes from the CPU could be upgraded with just a BIOS update, but the additional lanes provided by the chipset would not be upgraded.

800px-Socket_AM4_X370_multi_GPU.svg.png
 
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A bios update cannot enable PCIe Gen 4, unless the board and processor already support it in hardware. Since out X370 boards do not support PCIe gen 4, it is not physically possible to enable it.

The connections are the same so it is physically possible. PCIe 4 has stricter requirements for the traces. Originally AMD was going to let manufacturers decide if their boards met those requirements but then decided to just tell them they can't enable it in official BIOS' to avoid confusion.

They are allowed to enable it in beta though.
 
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My understanding is that current AM4, the CPU provides some PCI support, and that is just passed through. The chipset then provides additional support (usually just some additional PCI 2.0 from what I can gather on existing boards)... so the PCI lanes from the CPU could be upgraded with just a BIOS update, but the additional lanes provided by the chipset would not be upgraded.

Basically what I'd expect, with the addition that the board would have had to have been built to the PCIe 4.0 standard, even haphazardly. Seems unlikely to result in 100% support, and, AMD has been quoted as saying that this will not be enabled on Zen 2 CPUs.

I'll call it anyone's guess at this point as to whether or not it will work. If the link is constantly negotiating down due to signal issues, enabling PCIe 4.0 may even hamper performance.
 
Oh snap! My GA-AX370-Gaming K7 (rev. 1.0) supports the Ryzen 9 3950X 16 core processor! Of course I'd miss out on all of the cool overclocking features though from the 2700X era and whatever new overclocking stuff AMD is rolling out for the new processors.
https://www.gigabyte.com/Motherboard/GA-AX370-Gaming-K7-rev-10#support-cpu

Click the pic for a larger image.

View attachment 169185
Looks like a lot of their boards with the F40 update have their CPU support charts updated with most/all of the 3xxx chips on them. All of the B450 boards I use in current builds have support listed for all of them. I'm quite happy about that. :)
 
I have this board. While I'll probably get an X570 board, I'll probably get a CPU first, so this will be fun.
 
I have this board. While I'll probably get an X570 board, I'll probably get a CPU first, so this will be fun.
That's what I'm thinking too. I can grab a CPU as an upgrade for now. Then grab a X570 board later on so I can have access to Precision Boost 2 and the rest of the new stuff.
 
Oh snap! My GA-AX370-Gaming K7 (rev. 1.0) supports the Ryzen 9 3950X 16 core processor! Of course I'd miss out on all of the cool overclocking features though from the 2700X era and whatever new overclocking stuff AMD is rolling out for the new processors.
https://www.gigabyte.com/Motherboard/GA-AX370-Gaming-K7-rev-10#support-cpu

Click the pic for a larger image.

View attachment 169185

A lot of boards had all the Precision Boost added also. The only thing you really missed out on between X370/X470 was StoreMi. Personally, I'm hoping Asus gives some 3000 series love to the old B350 Strix board I have.
 
A lot of boards had all the Precision Boost added also. The only thing you really missed out on between X370/X470 was StoreMi. Personally, I'm hoping Asus gives some 3000 series love to the old B350 Strix board I have.
Maybe when I get an upgraded processor, I will be able to see the PB2 options. I bought StoreMi but I stopped using it. My hard drive never stopped chattering 24/7. It worked great though!
 
Maybe when I get an upgraded processor, I will be able to see the PB2 options. I bought StoreMi but I stopped using it. My hard drive never stopped chattering 24/7. It worked great though!

I get PB2 and PBO options when I use my Zen+ 2600 in the B350 board. I'm guessing we'll get a PB3 or PBO+ with the new CPUs which hopefully will continue to work with older boards. I get that PCIe 4.0 might not be an across the board "feature." But I can live without that as I don't have anything that would take advantage of it anyway. I'm guessing it's more marketing than performance.
 
Oh snap! My GA-AX370-Gaming K7 (rev. 1.0) supports the Ryzen 9 3950X 16 core processor! Of course I'd miss out on all of the cool overclocking features though from the 2700X era and whatever new overclocking stuff AMD is rolling out for the new processors.
https://www.gigabyte.com/Motherboard/GA-AX370-Gaming-K7-rev-10#support-cpu

Click the pic for a larger image.

View attachment 169185

Cool stuff. I found similar info about my UD3 X79 after I got it 3-4 years ago and then they put out a BIOS update that allowed a significant number of Xeon CPU's to be used with it. I never upgraded to one but I always thought it was neat to have the option. Sounds like Gigabyte continues this trend with their AMD support too. Glad to hear it and that could influence my choice when I do get to that Ryzen 2/3 build. Right now them and Asus are my main contenders.
 
x370 k5 supports 3950x too, cool deal. Now just gotta see how them lower perf chips overclock.
 
Hello, I have a Gigabyte AX370 Gaming 3 (GA-AX370-CF) Motherboard which was lucky enough to be upgraded to PCIe Gen 4 with the F41a BIOS update.

pcie4-ax370.png
 
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