PCIE lane specifics? And MOBO setup with two 4.0 Gen4.0 x16 units, each with full 16 lanes available.
PCIE lane specifics? And MOBO setup with two 4.0 Gen4.0 x16 units, each with full 16 lanes available.
You're asking about the compatibility of PCIe generations with physical slot configurations. It seems you're trying to match specific performance requirements using dual GPUs on an AM4 board. The idea is to have two slots, each supporting full or reduced lanes, and ensure they meet your speed expectations. Regarding the size, x16 slots can indeed have either 16 or 8 lanes depending on the generation, while x8 slots are less common. For a Gen4.0 x16 slot with 16 lanes, it should match the performance of a full Gen3.0 x16 slot. However, in the second slot you mentioned, only Gen4.0 x16x8 is available, which would limit the total bandwidth to 32 lanes instead of the desired 64. This could affect overall system performance, especially if you're planning to use multiple GPUs or run demanding applications. It's worth checking current MOBO listings for AM4 boards that support dual Gen4.0 slots with the required lane configurations.
AM4 supports up to 20 lanes from the CPU plus 4-6 lanes from the chipset. In most cases, using a GPU in a narrower slot doesn’t impact performance unless you’re at the top end.
Current consumer systems lack sufficient resources for this setup. Consider switching to platforms such as Threadripper or LGA 4677 for higher capacity. Many GPUs operate efficiently at lower lane counts like x8, though performance may be reduced. Using VMs for gaming is a common recommendation in these cases.
Looks like I figured it out—probably the X570 will offer more lanes than the B550 models.
These threadripper and similar services are expensive, even in used form, compared to what I can afford. It’s helpful to know whether upgrading from Gen4.0 x8 to Gen3.0 x16 would affect performance significantly or not.
Typically GPUs draw power from the CPU via PCIe connections, meaning a different chipset won't affect them. You're focusing only on the AM4 model, but if you're setting up a new build now, I'd recommend switching to AM5 for better performance. Speed should remain consistent. Generally, a Gen 3x8 setup works well for most GPUs, even lower-end ones. Lower link speeds are likely acceptable too.
Motherboard slots can support certain speeds, but the actual performance depends on the card used. For instance, a motherboard with PCIe Gen 4 x8 in an x16 slot will only operate at Gen 3 x8 speeds because of the physical connections, even though it supports that bandwidth.
your gaming rig runs at 7800X3D and 4080S, it leans more toward a workstation setup. why not go with AM5? the price difference would be several hundred euros higher. you’d need a 32-core CPU, which in AM5 equivalents would cost around 300-500 euros (used). plus, DDR4 RAM is also more affordable. it wouldn’t make much sense to switch to AM5 even if you prefer it.
It's reassuring, though, as the GPUs you're considering are all Gen4. This shouldn't pose an issue, but I'll remember it just in case.
Some x570 models can handle x8 x8 splits, enabling you to process cards in double the size simultaneously.