Question PCIe Lanes vs CPU Power for Gaming

CandiceJoy

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Jul 19, 2016
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So here's the thing (this is about gaming and basically nothing else). I currently have an i7-6700k. I have an rtx 3080 on the way. Yes yes, I need to upgrade. I realise that. The problem is I have a PCIe soundcard and usb card that take up 2 PCIe lanes, meaning that, on Intel's consumer architecture, I can only give ANY GPU 8x PCIe gen 3 lanes and no more. So the question is...do I upgrade to an intel consumer CPU (thinking 10700k) and still run the 3080 at 8x pcie3, or do I upgrade to an AMD Ryzen (thinking 3800xt), which comes with 24 pcie4 lanes, thus giving the 3080 a full 16 pcie4 lanes?

The Intel option is obviously faster for gaming, but I don't know how much 8x pcie3 lanes is going to matter vs the performance difference of the Intel option and the AMD option.
 
Can you post your system specs first(CPU,mobo,RAM,PSU)?

If I remember correctly if you're using a Z170 motherboard your CPU PCIe lanes will be used only by the first PCIe expansion slots... x16 for a single GPU and x8 for SLI(each GPU will use 8 lanes).

The other slots like PCIe X1, M.2, etc. are using the Z170 chipset provided 20 lanes that are connected to the DMI bus which has x4 3.0 bandwidth. That means that across those 20 lanes you're having that x4 bandwidth, so adding a lot of devices that take up a lot of bandwidth might lead to bottlenecks in terms of their speed(that's not the case for you... you're using only 2 lanes).

There's no link between those 16 PCIe lanes provided by your CPU to the GPU and the 20 lanes provided by the Z170 chipset to other slots(to your sound card and usb card for example that are using PCIe x1 slots I'm assuming). So, effectively you're still getting your full 16 3.0 lanes with your GPU(with your current one or the RTX 3080), as your sound card and USB card are using the chipset provided lanes.

You'll be getting your full 16 PCIe 3.0lanes for your GPU with the newer Intel platform too(Z490 +10700k) as the Z490 PCH will provide 24 PCIe 3.0 lanes and the GPU will take the allocated 16 lanes from your CPU.
 
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