Following this week’s launch of AMD’s new Ryzen 3000 series of processors, reports have once again begun circulating that PCIe 4 will be available on some existing 300 & 400 series boards. This comes despite AMD’s official statement last month that they would not be allowing the feature on older boards, as PCIe 4’s tighter signal integrity standards would have led to, at best, a highly fragmented market where some boards work, some boards don’t, and some boards may be outright marginal. At the time the company stated that the feature would be stripped from the AGESA that goes into the final Ryzen 3000 launch BIOSes for older boards.

So, to get right to the heart of matters, I reached out to AMD PR this evening to find out what’s going on with PCIe 4 support. The short version then is that no, AMD’s plans have not changed: PCIe 4 support will be disabled in the shipping AGESA for these boards.

Our plan is unchanged. For the reliability and consistency reasons cited at Computex, we still intend to disable PCIe Gen 4 for pre-X570 motherboards. That AGESA is being released to motherboard manufacturers soon.

As things stand, any boards that currently support the feature would be using pre-release AGESAs, and as we’ve seen with our own BIOS issues, the Ryzen 3000 BIOS situation is still evolving fast. So with AMD intending to permanently disable the feature – and prevent any workarounds – AMD’s goals haven’t wavered. At best, the few boards that have beta BIOSes with the feature will lose them in the future, unless users opted to stick with an unsupported (and almost certainly buggy) BIOS.

Going forward, proper PCIe 4 support will continue to require an AMD 500-series board specifically designed to meet the signal integrity requirements for the higher speed standard. Right now, this includes boards based on AMD’s X570 chipset; and while the company hasn’t announced other 500-series chipsets, we’re expecting to see more in due time.

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  • appleache - Saturday, July 13, 2019 - link

    I think it is more likely to give mb company a fair playground, since not all x470/450 are build equally, so some company opt to use better pcb, wiring(like asus) will have advantage give almost all their board pcie4 while others cannot. it kinda like review imbargo, make it somewhat a fair play. Reply
  • Galatian - Saturday, July 13, 2019 - link

    Not surprising. The X570 Chipset is actually just the I/O Die on GloFos 14nm process. Not only does AMD earn money with every X570 mainboard sold, they probably use the I/O Die to fulfill the wafer contract they signed with GloFo. AMD has all the interest to differentiate between X470 and X570. Reply
  • Averant - Saturday, July 13, 2019 - link

    People who are complaining about not getting retroactive PCIe Gen 4 support clearly do not understand what that entails. The standard requires power. LOTS more power. AMD is covering its ass by not releasing backwards compatibility because PCIe Gen 4 has the potential to -fry- your motherboard. Short of possibly very high-end boards, the circuit pathways cannot stably handle the extra power requirements, nor do they have adequate heat dissipation required to keep things cool. Have a good look at the preliminary boards. Most, if not all of them have on-board fan coolers for that reason. To be frank, I can't blame AMD for not wanting to be responsible for the IMMEDIATE backlash of people trying to RMA partner boards because their BIOS update fried them. You don't shoot yourself in the foot intentionally, and that is what it is tantamount to by AMD.

    For the record, I have an X399 board running TR2. Now, it's -possible- that my board could handle it, but I wouldn't want risking borking my $400 mobo over a feature that will not really improve anything for me. I have no PCIe Gen 4 devices. Video cards(I run a 2080) do not even fully saturate PCIe Gen 3 yet, so there would be negligible improvement to performance there, if any. Backwards compatibility would be nice, but not at the risk of fragging my very expensive-to-replace HEDT system.
    Reply
  • Death666Angel - Saturday, July 13, 2019 - link

    You are mixing all sorts of things here, mate. The signal does not require a lot of power, just very clear paths without crosstalk/interference and what-not. The power comes from the actual switching frequencies in the silicon. But enabling PCIe 4.0 on older chipsets would not make those chipsets suddenly be 4.0 compliant. They would still be 3.0 from CPU to chipset and 2.0 from chipset everywhere else. The only 4.0 lanes would be those 20 from the CPU to the x16 slot (GPU) and x4 slot (NVMe). That added power would be dissipated by the CPU heatsink or the thing would throttle (unlikely as the Wraith coolers have not increased in this new generation). Reply
  • Agaonm - Saturday, July 13, 2019 - link

    I mean I was able to mod a bios for my z170 to run an i5 8600 due to the work of modders on a forum so i can't see why the likes of asrock, gigabyte, Asus, msi and the likes who actively make bios and firmware couldn't hack it in regardless of the agesa code, I mean gigabyte boards started supporting it months ago before amds announcement but Asus literally just announced it on certain slots on certain boards even after amd said it wasn't supporting it so I imagine they might keep it going. This is also the kind of thing that Asrock would love doing like they done with the external bclk generated for 6th gen intel Reply
  • DanNeely - Saturday, July 13, 2019 - link

    Intel can't do anything about modders hacking firmware.

    AMD can tell the mobo makers that if they start doing it they won't get any more x570/etc chips.
    Reply
  • MASSAMKULABOX - Monday, July 15, 2019 - link

    hmmm .mobo mAkers can mod a bios and possibly enable pcie gen 4 ? or they can sell a new motherboard.. so old boards come back after being broken thru bad flash or gen4 doesnt work ? They will sell the new gtd Mobo every day of the day, and twice on Sunday Reply
  • mjz_5 - Saturday, July 13, 2019 - link

    I am amazed with what I read here sometimes Reply
  • Flunk - Saturday, July 13, 2019 - link

    I don't want to sound like a paid shill here, but everyone is assuming this is just because they can. Maybe they're disabling PCIe 4.0 for a reason. Reply
  • wilsonkf - Saturday, July 13, 2019 - link

    It depends on how far AMD will go. It is OK to drop official support while letting MB makers to put their own effect. It will be ugly if AMD try to prevent or even forces all MB makers to drop their support. Reply

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