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It's been a while I bought a motherboard. Sata (6gb/sec?) was godsend at the time. Smaller cables and connectors and nicer to keep tidy. Pet peeve of mine to

It's been a while I bought a motherboard. Sata (6gb/sec?) was godsend at the time. Smaller cables and connectors and nicer to keep tidy. Pet peeve of mine to keep it looking nice especially with some stacked hard-drives in the bay. Back then it was pretty clear what you might do with the slots available. Could someone fill me in with PCIe. What slots are available and are these mainly used now for graphics and SSD? SSD in slots is new to me which I haven't gotten around to yet.

zeroflow 6y ago
PCIe slots come either from the CPU or the Chipset. Typically, there are 16 lanes used per GPU and 4 per M.2 SSD. With older CPUs, you had to either reduce the lanes assigned to the GPU to connect an SSD to the CPU, or go through the chipset. With newer CPUs (newest intel or AMD Zen), the CPU provides 20 Lanes (16+4) for general use and in the case of AMD, 4 additional lanes for the chipset. If you want more lanes connected directly to the CPU, you have to go to HEDT or Server Chips with up to 128 lanes available. See this article for a typical block diagram of a AM4 system. https://www.guru3d.com/news-story/amd-ryzen-3000-new-block-diagram-about-pcie-4-on-matisse-and-x570-chipset.html https://www.guru3d.com/news-story/amd-ryzen-3000-new-block-d... Here you see, there are 1x16 / 2x8 lanes for GPU, and 4x PCIe/SATA combo ports from the CPU which can be used for connectivity. More lanes can be provided by the PCH (Chipset). Another example is in this artice by anandtech, which even lists the slots explicitly in the block diagram. https://www.anandtech.com/show/14657/the-asus-pro-ws-x570ace-motherboard-review https://www.anandtech.com/show/14657/the-asus-pro-ws-x570ace...
- jzer0cool 6y ago
  The block diagram helped! Great summary. Did some additional readings as I forgot all about PCH and came across south bridge / north bridge which were familiar sounding. As I understand, please correct me, summarizing parts what you wrote. So 16 lanes for GPU and the 4 (usually to PCH), which can be thought of as an extension? I'm not sure the right term but I guess this provides bus sharing through some mechanism so it does not affect the GPU lanes.
deleted 6y ago
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zeroflow 6y ago

PCIe slots come either from the CPU or the Chipset. Typically, there are 16 lanes used per GPU and 4 per M.2 SSD. With older CPUs, you had to either reduce the lanes assigned to the GPU to connect an SSD to the CPU, or go through the chipset. With newer CPUs (newest intel or AMD Zen), the CPU provides 20 Lanes (16+4) for general use and in the case of AMD, 4 additional lanes for the chipset. If you want more lanes connected directly to the CPU, you have to go to HEDT or Server Chips with up to 128 lanes available. See this article for a typical block diagram of a AM4 system. https://www.guru3d.com/news-story/amd-ryzen-3000-new-block-diagram-about-pcie-4-on-matisse-and-x570-chipset.html https://www.guru3d.com/news-story/amd-ryzen-3000-new-block-d... Here you see, there are 1x16 / 2x8 lanes for GPU, and 4x PCIe/SATA combo ports from the CPU which can be used for connectivity. More lanes can be provided by the PCH (Chipset). Another example is in this artice by anandtech, which even lists the slots explicitly in the block diagram. https://www.anandtech.com/show/14657/the-asus-pro-ws-x570ace-motherboard-review https://www.anandtech.com/show/14657/the-asus-pro-ws-x570ace...

jzer0cool 6y ago
The block diagram helped! Great summary. Did some additional readings as I forgot all about PCH and came across south bridge / north bridge which were familiar sounding. As I understand, please correct me, summarizing parts what you wrote. So 16 lanes for GPU and the 4 (usually to PCH), which can be thought of as an extension? I'm not sure the right term but I guess this provides bus sharing through some mechanism so it does not affect the GPU lanes.

deleted 6y ago

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