SSD speeds are slowing down due to Intel Core Ultra

SSDs do not reach maximum transfer speeds, and M.2 ports slow down on Z890 motherboards due to issues with Intel Core 200S processors.

The issue was discovered by SSD Review

During testing, a PCIe 5.0 drive with a possible speed of 14GB/s reached a maximum speed of 12GB/s on the Arrow Lake. The 2GB/s reduction in bandwidth occurs on newer processors due to issues with the PCIe lines for the M.2 slots on the motherboard. 

This problem only affects Arrow Lake processors. In testing, Z890 motherboards with PCIe 5.0 SSDs were unable to operate at 14GB/s. While in similar tests, previous generation boards function at this speed without any problems.

The testing was performed on Micron 4600 and Samsung 9100 Pro, which were connected to systems with Z790 and Z890 boards. As a result, on the Z790, 2 SSDs were able to reach 14.3 GB/s. While on the Z890, the peak speed was 12.3 GB/s. Also, these 2 drives were tested on an Asus Hyper M.2 PCIe card and showed no speed lag.

When bypassing the M.2 slot, the performance of random operations was still lower. Therefore, the delay is not related to a specific board manufacturer but is due to issues with the I/O Extender component in the Intel processor.