The wacky dual-screen Asus Zenbook does Core i9 better than the MacBook Pro
There are good Core i9 laptops and then there are bad Core i9 laptops. Perhaps to nobody's surprise, thicker Core i9 laptops are generally faster than the thinner ones despite them all carrying the same i9-8950HK CPU. The performance setback for the Core i9 MacBook Pro 2018 is the latest example of pushing the cooling solution a bit too far just to get the vaunted i9 brand in the marketing.
The next thinnest laptop with the i9-8950HK CPU is the Asus Zenbook UX580. Unveiled at Computex 2018, the Asus is just 18.9 mm thick compared to the 15.5 mm MacBook Pro 15 2018. Fortunately for Asus, that additional girth allows the UX580 to maintain base clocks even when subjected to extreme CPU loads.
To test this, we ran Prime95 to stress the Asus at 100 percent CPU load and then monitored clock rate behavior with HWiNFO. Core temperature jumps almost instantaneously to 96 C as shown by the screenshot below, but clock rate is nevertheless in the 3.6 to 4 GHz range compared to the 2.9 GHz base clock of the i9-8950HK. The high Turbo Boost clock rate does not last long, however, as it eventually stabilizes at 3.0 GHz. In other words, we can confirm that the Core i9 CPU in the Zenbook can maintain base clock rates at the very least with only short bursts of Turbo Boost.
We recently tested the Core i7 SKU of the MacBook Pro 15 2018 with a potential Core i9 SKU down the line to investigate its supposed throttling behavior. When considering that the same Core i9 CPU in the thicker Zenbook hovers around 90 C at base clock rates, however, it's tough to imagine how the even thinner Apple design can fare much better.