F5F Stay Refreshed Hardware Desktop PCIe lanes Z690 vs X570

PCIe lanes Z690 vs X570

PCIe lanes Z690 vs X570

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Maliwan99
Senior Member
346
06-24-2021, 12:20 AM
#1
Your answers are correct. Both platforms limit PCIe lanes to a maximum of 28.
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Maliwan99
06-24-2021, 12:20 AM #1

Your answers are correct. Both platforms limit PCIe lanes to a maximum of 28.

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jaefrh
Member
180
06-24-2021, 07:21 AM
#2
Only 24 lanes are available on both systems (including 4 from the chipset), typically reserved for an x16 GPU and two x4 NVMe drives.
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jaefrh
06-24-2021, 07:21 AM #2

Only 24 lanes are available on both systems (including 4 from the chipset), typically reserved for an x16 GPU and two x4 NVMe drives.

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BlackAce_44
Member
52
06-26-2021, 06:22 AM
#3
However, the chipsets function as a PCIe switch, allowing more usable PCIe lanes than available. The Z690 provides an additional 28 lanes from the DMI, bringing the total to 48 PCIe lanes. You won't be able to fully utilize all these lanes simultaneously, though it's uncommon to run every device at maximum capacity on a desktop.
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BlackAce_44
06-26-2021, 06:22 AM #3

However, the chipsets function as a PCIe switch, allowing more usable PCIe lanes than available. The Z690 provides an additional 28 lanes from the DMI, bringing the total to 48 PCIe lanes. You won't be able to fully utilize all these lanes simultaneously, though it's uncommon to run every device at maximum capacity on a desktop.

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Malthe581
Member
140
06-27-2021, 10:56 PM
#4
Each motherboard can choose from various configurations. For instance, with Z690, the manufacturer decides whether to provide two x8 PCIe 5.0 slots or one x16 slot. The selection is determined by the maker, not Intel. Below are the schematic diagrams to illustrate the available choices.
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Malthe581
06-27-2021, 10:56 PM #4

Each motherboard can choose from various configurations. For instance, with Z690, the manufacturer decides whether to provide two x8 PCIe 5.0 slots or one x16 slot. The selection is determined by the maker, not Intel. Below are the schematic diagrams to illustrate the available choices.

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SillyDragon
Senior Member
586
06-28-2021, 01:14 AM
#5
Thanks! Those diagrams helped me figure out my lane counts. I’m not focused on extra lanes from the chipset since I want to pack as much as possible into my desktop without CPU or chipset bottlenecks. The GPU is an X16, with the NVMe setup using two X4 CPUs and an X4 chipset. The network interface is a dual-port 25GbE requiring PCIe 4.0 X4 to prevent slowdowns. I have a 100TB NAS on the network and everything should work fine. It seems my desktop choices are limited—I’m leaning toward a Zen2 Threadripper Pro. I don’t know if Zen3 TRP will be available soon for system builders.
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SillyDragon
06-28-2021, 01:14 AM #5

Thanks! Those diagrams helped me figure out my lane counts. I’m not focused on extra lanes from the chipset since I want to pack as much as possible into my desktop without CPU or chipset bottlenecks. The GPU is an X16, with the NVMe setup using two X4 CPUs and an X4 chipset. The network interface is a dual-port 25GbE requiring PCIe 4.0 X4 to prevent slowdowns. I have a 100TB NAS on the network and everything should work fine. It seems my desktop choices are limited—I’m leaning toward a Zen2 Threadripper Pro. I don’t know if Zen3 TRP will be available soon for system builders.

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SkyInsane
Senior Member
718
07-02-2021, 04:27 PM
#6
You're considering specific motherboards. They may restrict your lane usage, but both the x570 and z690 models can meet your requirements as you described. The chipset shouldn't be a major issue here, since it's uncommon to hit both SSD and network speeds simultaneously, especially with the x8 connection on z690.
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SkyInsane
07-02-2021, 04:27 PM #6

You're considering specific motherboards. They may restrict your lane usage, but both the x570 and z690 models can meet your requirements as you described. The chipset shouldn't be a major issue here, since it's uncommon to hit both SSD and network speeds simultaneously, especially with the x8 connection on z690.

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OhMyOry
Junior Member
15
07-08-2021, 03:45 PM
#7
Fair enough, but I think the OP's concern was about how many peripherals you can attach, which is limited by what I mentioned (unless OP modifies the setup). Unless you're okay with reducing something, you'll need to use a high-end platform like Threadripper or Xeon-W. The Zen3 TR Pro should work later this year (provided it matches the Zen2 TR Pro experience: OEM first, then regular sales).
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OhMyOry
07-08-2021, 03:45 PM #7

Fair enough, but I think the OP's concern was about how many peripherals you can attach, which is limited by what I mentioned (unless OP modifies the setup). Unless you're okay with reducing something, you'll need to use a high-end platform like Threadripper or Xeon-W. The Zen3 TR Pro should work later this year (provided it matches the Zen2 TR Pro experience: OEM first, then regular sales).

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Charliemc909
Posting Freak
898
07-08-2021, 07:27 PM
#8
i was considering z690 mobos since i believe am4 is no longer supported, and ddr5/pcie5 will let me upgrade in a few years. i haven't explored the x570 models as much because of that. for z690... msi meg ace or godlike if the gods permit, these are the only boards i've found that support x16/x4 slots and specifically avoid reverting to x8/x8.
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Charliemc909
07-08-2021, 07:27 PM #8

i was considering z690 mobos since i believe am4 is no longer supported, and ddr5/pcie5 will let me upgrade in a few years. i haven't explored the x570 models as much because of that. for z690... msi meg ace or godlike if the gods permit, these are the only boards i've found that support x16/x4 slots and specifically avoid reverting to x8/x8.