How many PCIe Lanes do I need for my toys

[Pooh]

Just wondering down the road if moving from a Threadripper to a non HEDT system is sensible.

I currently on a TRX40 motherboard with 64 PCI lanes

Here's a breakdown:

• CPU: Provides 24 PCIe 4.0 lanes.
• TRX40 Chipset: Provides 36 PCIe 4.0 lanes.
• Total: 24 (CPU) + 40 (Chipset) = 64 PCIe lanes.

The motherboard uses these lanes to support various components, including:

• PCIe Slots: 4 full-length PCIe slots (2 x16 and 2 x8, all PCIe 4.0).
  
  
• M.2 Slots: 3 Ultra-Fast NVMe PCIe 4.0 x4 M.2 slots.
  
  
• Other Components: SATA ports, network controllers, and other onboard devices.

So I've got

1. 5090 GPU - 16 lanes
2. pci expansion card ( NVME ) - 4 lanes
3. 3 X onboard NVME Drives - 12 lanes in total
4. RAID card for my spinners - 4 lanes

That comes up to 36 lanes, now i can't figure out how many lanes are needed for the USB Ports, SATA ports (all disabled on my mobo), 2 NICs, sound chip etc etc and just the rest of the gubbings that are needed to make the Mobo run.

From research the 9800x3D has 28/24 (Total/Usable) PCI lanes, so unless I'm missing something it's a bit of a non-starter.
Seems similar for the Intel Core Ultra 9 285 with 24 lanes

What do you think.

 

[Tetras]

From research the 9800x3D has 28/24 (Total/Usable) PCI lanes, so unless I'm missing something it's a bit of a non-starter.

AM5 CPUs have 4x lanes for a PCI-E 5.0 M.2 slot, 4x PCI-E 5.0 lanes for a second M.2 slot or other use, plus 16 lanes for the graphics card. If USB4 is present, they will usually steal 4 from the CPU.

The chipset can theoretically provide enough for additional M.2 and a 4 lane slot, but lane sharing between M.2 and secondary PCIE slots is common.