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Old 12-07-19, 01:08 PM
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Avet Avet is offline
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Quote:
Originally Posted by demonking View Post
Doesn't this kind of contradict everything we have been told previously on how PCI-e 4 needed additional hardware that was not in use for PCI-e 3 and that the chipsets would need cooling to manage the additional load on the chipset?
And that this was the justification for the additional price (extra layers needed in the PCB to support the additional connections and more expensive chipset)?
I mean a crosshair 7 is around the 270 to 300 price where as a crosshair 8 is 400.
Something is not right here, admittedly a bonus for anyone on the x470 but if you have bought a x570 because everyone involved told you that you had to if you wanted PCI-e 4 (AMD, board manufacturers, reviewers ect) is kind of misleading and possibly liable.
https://www.anandtech.com/show/14477/amd-confirms-pcie-4-not-coming-to-older-motherboards
The prominent issue is signal integrity. You can see that m.2 slots are just below the CPU. They are very close and, as stated in the article, those are primary m.2 slots with CPU lanes. Also with PCIe x16 slot, only boards that don't support SLI/CF have some support for PCIe 4.0. Again, they have only one PCIe slot that is connected to CPU. Boards that have lane dividers (a bunch of those square chips that you see between PCIe slots) and support for SLI/CF, in this case, higher-end boards, don't support PCIe 4.0. The second slot is very far from the CPU, and lane dividers don't support PCIe 4.0. That why you need better-built PCBs, and different components. ITX boards have extremely densely packed PCBs, with traces going all around everywhere so I assume it is too noisy to keep adequate signal integrity for PCIe 4.0, hence no support.

PCH has nothing to do with support on x470 boards because support is related only to CPU lanes.

If you know very basic stuff about PCIe lanes, and how stuff is organized on the motherboard it is very logical and makes sense.

If there are any engineers there please correct me if I am wrong.
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