Question:

How does the x570 chipset Link speed affect the performance of nvme drives with different PCIE generations? >
> I have a system with an x570 motherboard, a Ryzen 9 5950X CPU, a Gainward RTX3080TI GPU, and three nvme drives: a Crucial T500 2TB and a Corsair Force MP600 1TB (both PCIE4), and a Samsung 970 Evo Plus 1TB (PCIE3) on an extension card. I noticed that when I set the chipset Link speed to PCIE4, the read and write speeds and the access times of the second and third nvme drives (connected to the chipset) are very inconsistent and lower than expected. However, when I set the chipset Link speed to PCIE3, the performance of these drives improves significantly and matches the PCIE3 standard. Is this a known issue with the x570 chipset? Does it have problems handling devices with mixed PCIE generations? How can I fix this problem?

Answer:

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> The x570 chipset is the latest and most advanced chipset for AMD Ryzen 3000 and 5000 series processors, supporting the PCI-Express 4.0 interface, which offers twice the bandwidth of PCI-Express 3.0. This means that devices connected to the x570 chipset, such as M.2 NVMe SSDs, can achieve faster data transfer rates and lower latency, improving the overall system performance and responsiveness. However, not all NVMe SSDs are compatible with PCI-Express 4.0, and some users may encounter issues when using NVMe drives with different PCIE generations on the x570 chipset. >
> One such user reported that he had three NVMe drives on his system: a Crucial T500 2TB and a Corsair Force MP600 1TB (both PCIE4), and a Samsung 970 Evo Plus 1TB (PCIE3) on an extension card. He noticed that when he set the chipset Link speed to PCIE4, the read and write speeds and the access times of the second and third NVMe drives (connected to the chipset) were very inconsistent and lower than expected. However, when he set the chipset Link speed to PCIE3, the performance of these drives improved significantly and matched the PCIE3 standard. He wondered if this was a known issue with the x570 chipset, and if it had problems handling devices with mixed PCIE generations. He also asked how he could fix this problem. >
> To answer his question, we need to understand how the x570 chipset communicates with the CPU and the devices connected to it. The x570 chipset has a total of 16 PCIE lanes, which are divided into two groups: 4 lanes for the CPU-chipset link, and 12 lanes for the devices. The CPU-chipset link can operate at either PCIE4 or PCIE3, depending on the chipset Link speed setting in the BIOS. The devices can also operate at either PCIE4 or PCIE3, depending on their compatibility and the slot configuration. However, there is a catch: the chipset Link speed setting affects not only the CPU-chipset link, but also the devices connected to the chipset. This means that if the chipset Link speed is set to PCIE4, all the devices connected to the chipset must also operate at PCIE4, regardless of their native PCIE generation. Conversely, if the chipset Link speed is set to PCIE3, all the devices connected to the chipset will operate at PCIE3, even if they are capable of PCIE4. >
> This explains why the user experienced performance issues with his NVMe drives when he set the chipset Link speed to PCIE4. The second and third NVMe drives, which were connected to the chipset, had to operate at PCIE4, even though one of them was a PCIE3 drive. This caused compatibility problems and reduced the performance and stability of the drives. On the other hand, when he set the chipset Link speed to PCIE3, the second and third NVMe drives operated at their native PCIE generation, which eliminated the compatibility problems and improved the performance and stability of the drives. >
> Therefore, the solution to this problem is to set the chipset Link speed to match the PCIE generation of the devices connected to the chipset. If all the devices connected to the chipset are PCIE4, then the chipset Link speed can be set to PCIE4 to take advantage of the higher bandwidth and lower latency. However, if any of the devices connected to the chipset are PCIE3, then the chipset Link speed should be set to PCIE3 to avoid compatibility issues and performance degradation. This way, the user can ensure the optimal performance and reliability of his NVMe drives on the x570 chipset.