15-05-2025
Intel Core Ultra 200 CPUs May Bottleneck Gen 5 SSDs
It seems that Intel Core Ultra 200S CPUs have a design issue that can cause some latency when using Gen 5 SSDs. The SSD Review noticed that it wasn't getting anywhere near 14GB/s when plugging SSDs into the M.2 slots of Intel Z890-based motherboards. After significant testing and checking in with Intel, The SSD Review narrowed the suspect list to the CPU—when the SSD is plugged into the M.2 slot.
The latency is dramatic: 12GB/s sequential read speeds have been the norm for the SSD reviewer with Core Ultra 200S CPUs in the test bench. Random write speeds are apparently lower than expected, too.
Kudos go to Intel for responding to The SSD Review. It pointed out that the die-to-die path on its CPU is a little longer for Gen 5 memory than for other PCIe lanes.
'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,' Intel noted to The SSD Review. 'However, any variations are contingent upon the specific workload and the capabilities of the PCIe endpoint device.'
Credit: Intel
As Tom's Hardware notes, Raptor Lake doesn't appear to suffer the same problem. The SSD Review tested the issue with Micron Pro and Samsung 9100 Pro SSDs on its test bench with Arrow Lake and Raptor Lake setups. The different CPU/motherboard combos highlighted the problem: The Raptor Lake setup logged 14.3GB/s, while the Arrow Lake setup landed at 12.3GB/s. That's not what you want to see from newer, more advanced hardware.
That's an annoying problem, for sure, but you can circumvent it by picking up a PCIe add-in card instead of an M.2 card. The SSD Review had no problem getting full speeds from the PCIe 5.0 lane.
And, although we're generally loathe to take the 'grin and bear it' approach, it may be the easiest path for you if you already have Gen 5 memory in an M.2 slot on an Intel Z890 board. After all, as The SSD Review points out, even at 12GB/s, the setup provides much faster speeds than a rig with Gen 4 speeds. If you have been using your PC without complaint until now, there's really no need to make a change.
