Core Ultra 7 255U can run much slower than the Core Ultra 7 155U depending on the laptop

The Arrow Lake-U Core Ultra 7 255U is now widely available to replace last year's Meteor Lake-U Core Ultra 7 155U. We've tested three individual laptops thus far each equipped with the Core Ultra 7 255U to see how the CPU stacks up against its predecessor, but initial impressions have been lukewarm.

Our latest Arrow Lake-U test unit is the HP 17t which is a budget-grade 17.3-inch multimedia laptop. Unfortunately, its CPU not only runs slower than others with the same processor, but its clock rates tend to cycle when stressed leading to uneven performance or frame rates when gaming. The cycling performance is exemplified by our CineBench R15 xT loop test results below.

As for any performance benefits over last year's Core Ultra 7 155U, the Core Ultra 255U can be up to 50 percent faster in the best case scenario or almost 20 percent slower in the worst case. For example, the Core Ultra 7 255U in the Lenovo IdeaPad 5 2-in-1 16 can run up to 50 percent faster than the Core Ultra 7 155U in the HP Envy 17, but the Core Ultra 7 155U in the Lenovo ThinkPad E14 G6 can run notably faster than the Core Ultra 7 255U in the HP 17t. Throttling behavior and cooling potential are inarguably significant factors when it comes to shopping between these two processor generations perhaps even more so than their actual names.

More information and benchmarks on the Core Ultra 7 255U can be found on our review of the HP 17t.