Intel stopped putting an i in its processor names when the Core Ultra brand arrived. The last Core i9 mobile parts belonged to the 14th generation, and everything at the top of the stack since then carries Core Ultra 9 on the badge. Searching for a Core i9 Lenovo lands you on Core Ultra 9 machines, which are the direct successor.
Two very different chips share that tier. HX parts are cut from desktop silicon, run at high sustained wattage and take replaceable DDR5 modules, which is what sits inside Legion and Legion Pro gaming machines. H-class and X-class parts are thinner-chassis designs with a larger integrated Arc graphics allocation, used in Yoga and ThinkPad flagships.
Which one you need follows from the graphics card rather than the processor badge. A Legion with an HX chip exists to feed a discrete NVIDIA GPU; a Yoga with an H-class chip exists to last a working day on battery.
The naming change is not cosmetic. Intel split its flagship mobile tier into families that share a number and share little else, and Lenovo fits both into ranges built for opposite purposes.
HX chips come off desktop dies and draw far more power under load than a slim chassis can dissipate, which is why they only appear where there is cooling volume to spend. H and X-class parts cap much lower, trading peak throughput for battery life and quieter fans. A Core Ultra 9 HX and a Core Ultra 9 H are not interchangeable despite sharing a number.
Lenovo's Legion and Legion Pro machines have run the 24-core Core Ultra 9 275HX through this cycle. Intel refreshed the platform in March 2026 with the Core Ultra 9 290HX Plus, rating it at up to 8% higher gaming performance than the 285HX across a 32-game average at 1080p high settings, most of that coming from a die-to-die link running up to 900MHz faster.
HX laptops use SO-DIMM slots, so DDR5 can be added or swapped after purchase, typically two slots and occasionally four in a larger Legion Pro chassis. Thin-and-light flagships solder their memory instead. If you expect to double capacity in two years, the chassis class decides whether that is even possible.
A flagship CPU behind an entry GPU puts the money in the wrong place for gaming. Legion configurations run from an RTX 5060 up to an RTX 5090 with 24GB of GDDR7, and the GPU governs frame rates at 1440p and above while the processor matters most for simulation, strategy titles and encoding a stream. One model line can span several GPU tiers, so read the listing.
Sustained wattage is a thermal problem before it is a silicon one. Legion machines use vapour-chamber cooling to hold high combined processor and graphics power through long sessions, which is why identical chips behave differently in thinner bodies. Keep the intakes clear and accept fan noise under load, because a flagship HX part cannot be quiet and fast at the same time.
Decide the job first, whether that is sustained rendering, gaming at a fixed resolution, or portable multitasking. Then read the chip suffix, the memory type and the GPU on the listing, because those three lines say more than the model name.
