According to my research and the information from Intel, both models have the same number of cores, but the Ultra 7 is clocked slightly faster and has a better graphics unit. Otherwise, they are very similar. With such a small difference, my conclusion is that if you need a little more graphics performance and a little more CPU power for more multitasking or slightly more demanding applications, go for the Ultra 7 and otherwise the Ultra 5 is the best choice.