AMD: Pre-X570 boards will not support PCIe Gen 4
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fantaskarsef
Tbh, I expected that. It's not big deal though.
Fox2232
I doubt that signaling is an issue on such short distance. Linus did test PCIe 3.0 extension cable after extension cable and reached like 4 or six meters on PCIe 3.0 before he run into issue.
Sad, it would be nice to have PCIe 4.0 between 1st slot GPU and CPU on my quality x470 board. Nice, but unnecessary.
nevcairiel
PCIe 4.0 has much more stringent requirements, though. On a board with multiple x16 slots, you'll already need re-drivers to enhance the signal to reach the bottom slots at full signaling strength.
Any test with PCIe 3.0 doesn't prove anything, since these things often interact exponentially. Also note that signaling in motherboard traces and in shielded cables of an extender is actually quite different, and shielded cables can go further without as much loss - but thats not an option for putting inside the PCB.
asturur
Would have made x570 useless i believe. What does it do other than giving you pci express 4?
I belive someone will tweak the bios to try it out
Kaarme
I recall there were articles about the challenges for the mobo manufacturers back when it was first talked about how the next gen Ryzen will bring PCIe 4.0.
I don't see why they couldn't leave the option enabled for older mobos, turned off by default, of course. It's not like the old things would be marketed as PCIe 4.0 capable, after all. Their boxes/marketing material were made a long time ago, well before PCIe 4.0 was anywhere near actual use. If a mobo happened to work for some reason, swell, if not, that's to be expected. However, I'm sure the mobo manufacturers would rather sell new mobos. They must love the Intel scheme more in the long run. The AMD situation probably worked for them because there was much growth to be expected with Ryzen in the beginning, after all the dull years of Intel dominance and zero development. But if a Ryzen user isn't willing to buy a new mobo even after years of use and upgrading the CPU itself, it's a financial problem for the mobo makers.
nevcairiel
Having an option that doesn't work is a support nightmare, and the points about confusion cited as the reason still stand.
nevcairiel
The chipset being connected through PCIe 4.0 is a much bigger deal then getting PCIe4 to the GPU, because it doubles the bandwidth the chipset has available. And this of course only works if the chipset is PCIe4 capable, so only X570.
sverek
We don't know Matisse performance difference between X470 and X570. Hopefully it's minimal.
Venix
[spoiler]https://i.imgflip.com/32irte.jpg [/spoiler]
at least i think there might be attempts for it :P
Fox2232
I would like to see extension cards/cords for PCIe 4.0. This may hinder system builders a lot then. And something that sensitive does not sound right either.
Things called standard are supposed to work. Does that means that dream of external PCIe 4.0/5.0 devices is gone?
Seems really weird to go from 10 interconnected PCIe 3.0 extensions 6 meters long working connection down to problems directly connecting on MB itself on few centimeters distance.
nevcairiel
As mentioned above, PCB traces and cables are different things. Cables can be shielded much better. And worst case, you'll get active components like re-drivers to boost the signal.
Jawnys
im running a 2700x on a b350 board, and my benchmark are pretty much the same as those in x470, they re within the margin of error, so i would say it should be pretty close, only thing i see being better onn x570 aside from pci-e 4.0 is the memory controller, if you can really reach 4000mhz on ram, then i guess the benchmark will be better on x570 if you have higher ram speed, but thats pretty much it, on equivalent ram speed im pretty sure it ll be the same
Fox2232
You should check that video for what kind of basic cables they used. They are not bad, but they are as passive as cable can get. + resistance on each connection.
[youtube=q5xvwPa3r7M]
You can skip his usual BS, things start around middle of video.
phatbx133
Sound like they force us to buy x570 mobo's, I know there are some x370 and x470 can run PCIe 4.0 but all vendors want to sell x570 as much they can profit it.
If you have x370, maybe good upgrade to x570.
If you have x470, maybe good upgrade to x670 in the future.
(Bios mod might be able enabled PCIe 4.0 anyhow) Keep eyes on that someone dare it.
2 cents.
vbetts
Moderator
Not sure how this is important. Even current PCIE 3.0 the most bandwidth used are from NVME drives or just PCIE drives and they definitely do use that bandwidth but it's not like we have a number of PCIE 4 enabled drives yet.
tunejunky
but that's the brilliance of this move - they paid Phison for a new ssd controller for pcie 4.0 and they have (rt now) four suppliers of pcie 4.0 storage.
as gamers most of us shrug this off...but if you're a "content creator" dealing with massive files, a pcie 4.0 m.2 or slot ssd is worth the money from day one.
and with Ryzen 2 supporting 40 lanes of pcie 4.0, there are plenty of professional applications to take advantage of the bandwidth already.
schmidtbag
I think that was a fair statement by AMD. It might not be the answer customers want to hear, but it's better than AMD's reputation accidentally getting tarnished because of cheaply made mobos.
Yeah, I would've expected at the very least that the primary x16 slot feeding straight from the CPU would retain 4.0 specs. Isn't it mostly just a direct connection? Surely the signal quality couldn't diminish that much.
I would hope at least some brands, such as Asus, would allow for an experimental feature, where by default it uses 3.0 but you have the option to override it.
Isn't that big of a chicken and egg problem? There aren't going to be any PCIe 4.0 devices if there are no boards to support them. One of the appeals of the AM4 platform is its long-term support.
JamesSneed
If testing shows no performance loss on x370 my x370 motherboard will have a Ryzen 3000 slapped into with no other upgrades. Since first gen Ryzen didn't OC all that well there are a ton of us sitting on those 1700x chips that Ryzen 3700x would be a huge upgrade especially value wise if it can OC decently well.
schmidtbag
Well, there will be some performance loss if you count XFR (even X470 has improvements there), and depending on what your board is, the VRM might limit your OC. But I assume you overclock, and chances are your X370 will have a "good enough" VRM. Since we're probably not going to see any GPUs that'll saturate PCIe 3.0 @ x16 any time soon, it's very likely you won't have any performance loss.
Kaarme
I don't think so. Pre-x470 boards aren't supposed to support PCIe 4.0, so there's no need to offer support for such a functionality. Every mobo model needs its own bios release anyway, so a manufacturer could check some of their models to see if the first 16x port seems to work with PCIe 4.0. If it seems to, make the bios switch visible. Add a warning to it, perhaps.
However, like I said, I don't see why they would do such a thing from a practical point of view since it could rob them of some new sales. I might even believe they have had some talks about this with AMD, to see what sort of incentives each generation would offer, to balance the CPU compatibility remaining there, as opposed to Intel's scheme. So far the generations have had at least something little. PCIe 4.0 might be the main thing for x570. It would certainly be more visible in marketing than x470's benefit over x370.
