PC motherboard for client setup
PC motherboard for client setup
He has a special project with two 3090 GPUs—one for gaming/streaming and another for data science. He needs a motherboard that supports Intel 12th Gen with DDR5, but can handle different speeds: 16x for the first GPU and 8x for the second. So far, no board meets those requirements, so he’s looking for help from the community. The build will also include a Gen 4 NVMe drive, which affects PCIe lane usage.
Checked the second option at just 8x. Thought about using a dedicated server setup and running both at 16x, but unsure if that would be practical. Dual 4.0 x16 might work, though I’m not entirely confident.
Intel's latest consumer chip isn't compatible with this feature. The processors can only handle up to 20 PCIe lanes, limiting options to configurations like x16+x4 or 2x x8+x4. A dual x16 setup isn't possible without switching platforms. It's unclear if any upcoming systems will support it, especially regarding DDR5 compatibility.
If we can handle both at x16, that would be ideal! I mentioned 8x because many boards weren’t set up for dual 16x yet. I thought choosing something that works for both would be better since once the VRAM is in place it mainly affects performance rather than PCIe speed.
The lanes from the PCH will be slower, but once the data science model runs in VRAM it won’t rely much on PCIe communication. For the platform, we’ll need something capable of handling this workload—preferably an AMD board if possible. I’m looking for general guidance on what to aim for.
Theoretically, yes. GPUs are mostly confined to CPU-defined lanes, while PCH lanes tend to serve other functions like PCIe M.2 or x4 slots. I don’t know of a motherboard with an exclusive x8 PCIe connection.
For specialized setups, you’ll find dedicated workstations or servers. AMD’s Threadripper offers numerous PCIe lanes suitable for dual x16 connections. Intel’s current workstation line is Xeon-W, though details are less clear. I’d recommend starting with the 3000 series Threadripper. All of these support ample PCIe 4.0 lanes for two x16 ports.
Note: Some AMD desktops were reported to have more PCIe lanes than listed, but they also lack DDR5 support. Next-gen systems may include DDR5 and additional lanes. The upcoming AMD AM5 platform is expected to improve this situation.
Discussing lane allocation, my ASRock B450 Pro4 features 2600X PCIe 3.0 x16 (direct to CPU), PCI 2.0 x8, two PCI 2.0 x1 slots, and a possible PCI 3.0 x4 M.2 slot (direct to CPU). Some lanes are shared with the chipset I/O, while the second M.2 and two SATA ports also use shared lanes.