Across our Intel Arrow Lake coverage, including Tarinder’s Core Ultra 9 285K review, it’s clear that Team Blue’s latest chips suffer from surprisingly high latency. While this can have an impact on memory performance, this trait is also affecting storage too.
Folks at The SSD Review identified the issue with Core Ultra 200S processors, after an SSD capable of 14GB/s speeds was only running at 12GB/s on an LGA1851 system. Importantly, this issue isn’t to do with the storage or motherboard and instead boils down to an architectural problem with Arrow Lake.
The SSD Review contacted Intel and received the following response:
Intel can confirm that the PCIe Lanes 21 to 24 Gen5 root port on Intel Core Ultra 200S series processors may exhibit increased latencies compared to the PCIe Lanes 1 to 16 Gen5 root ports, owing to a longer die-to-die data path. However, any variations are contingent upon the specific workload and the capabilities of the PCIe endpoint device.
Intel
The root of the problem lies in Intel’s new multi-chiplet design, which includes an I/O Extender (IOE) tile. The latter manages PCIe lanes 21 to 24, typically used for the main M.2 slot. Data travelling through the IOE experiences higher latency due to the longer die-to-die communication, resulting in reduced SSD performance.
On the other hand, the PCIe lanes 1 to 16, managed by the System-on-Chip (SoC) tile, do not exhibit this issue. This meant that installing the same SSD on the PCI 5.0 x16 slot using an add-on card allowed it to reach its full 14GB/s speed. Also, note that this issue is specifically related to PCIe 5.0 NVMe SSDs which can reach speeds around 14GB/s, meaning that slower or older SSDs shouldn’t be affected.
This is an another unfortunate setback for Core Ultra 200S processors, following their problematic launch and woeful retail performance. While most consumers won’t have the likes of Samsung 9100 Pro in their system, the least one can expect is that it would run at full speed.
