It's reasonably common knowledge among computing enthusiasts that for a decent budget, you can get yourself either a high-performance workhorse of a laptop but must contend with its considerable physical heft, or for a similar price, you could get a well-built, low-powered thin & light laptop that won't really give you the oomph you might require at times for heavier tasks.
Consequently, it's also known that the best of both worlds - a powerhouse built into a slim package with a few apparent but tenable compromises - would set you back a significant premium. This particular niche, you'd find, is occupied by generally well-known machines such as Dell's XPS 15, HP's Elite lineup of laptops, and, of course, Apple's latest refresh to its top-of-the-line MacBook Pro models.
Or so Apple would have you believe. A number of tests run by tech YouTuber Dave Lee reveal that Cupertino's attempt at sticking a high-TDP Intel chip into a pre-existing laptop chassis completely unoptimized for it fails miserably: according to him, the hexa-core i9 processor built into the recently released refresh of the 15" MacBook Pro struggles to maintain its base clock speed of 2.9GHz - leave alone its advertised 4.8GHz boost speed - with it throttling all the way down to a measly 800MHz in order to cut down on temperature spikes.
Lee's benchmarks reveal that not only does the i9 model of the 2018 MacBook Pro run slower than its i7 sibling, but also falls behind the i7 variant of the 2016 MacBook Pro. He further deduces the source of this limitation by running the same benchmarks by keeping the laptop in a dry-freezer, which was the only way he manages to obtain better, more expectable numbers from it.
The i9 chip would, ideally speaking, have been a godsend for those who make a living out of spending hours in Lightroom and Premiere Pro, but the issues that seem to plague its host device make it an extremely hard sell, and that's without even bringing its base $2,800 price into the equation. The way things appear right now, you're legitimately better off saving $400 and opting for the "lower-tier" i7 model.
Image: Dave2D (YouTube)