Intel has quietly added the Core Ultra 7 251HX to its Arrow Lake HX lineup, skipping any formal announcement. The chip simply appeared on the Intel website a few weeks after it surfaced in Lenovo Legion 5i 2026 and MSI Raider 16 HX listings. The 251HX is an 18-core, 18-thread part with 6 Performance cores and 12 Efficient cores, slotting between the Core Ultra 5 245HX and the Core Ultra 7 255HX. Compared to the 255HX, it drops two P-cores and loses two threads, but keeps the same 12 E-cores and 30 MB of Smart Cache. TDP range stays identical at 55 W base and up to 160 W maximum turbo power. Max Turbo comes in at 5.1 GHz, 100 MHz below the 255HX, but the E-core base clock actually jumps 700 MHz to 2.5 GHz, and the P-core base is up 500 MHz as well at 2.9 GHz. Memory support goes up to DDR5-6400.

The integrated graphics drop to three Xe3 cores clocked up to 1.8 GHz, down from four on the 255HX, which also trims AI performance from 33 TOPS to 30. Not a dramatic difference, but worth noting if NPU performance matters for a specific workload. As an endnote, the Core Ultra 7 251HX sits between the Core Ultra 5 245HX with its 14 cores in a 6P+8E layout and 24 MB of cache, and the 20-core Core Ultra 7 255HX and 265HX sitting above.