ArsTechnica's Andrew Cunningham published his review of the new MacStudio today. In his review, he confirmed that MacStudio with the M4Max chip lacks a high-power mode for intensive workloads. He also tested a high-end MacStudio equipped with an M3 Ultra chip, but didn't mention that model's high-power mode either.
According to the Geekbench database, the MacStudio evaluation machine is running macOSSequoia15.3.
Apple says High Power Mode allows the Mac's fans to run at higher speeds, and this additional cooling allows the system to provide higher performance for graphics-intensive sustained workloads such as 8K video color grading. On supported Macs, this setting can be turned on when the computer is running on battery power or plugged in.
High Power Mode is currently available on 14-inch MacBook Pro models with M3Max, M4Pro, or M4Max chips, 16-inch MacBook Pro models with M4Pro or M1Max through M4Max chips, and Mac minis with M4Pro chips.
Given that MacBook Pro models equipped with the M4Max chip offer a high-power mode, Apple seems to be intentionally not offering a high-power mode on the Mac Studio equipped with the same chip. This could simply be because the MacStudio is a large desktop computer, which means a high-power mode is never necessary due to lack of battery life or thermal limitations. However, we haven't confirmed the real reason for Apple's decision. Anyway, it probably doesn't matter.
Cunningham said in last year's Macmini review that while fan noise was "significantly increased," the performance gains from high-power mode were "largely negligible." However, he also admitted that his testing period was short and that "during prolonged activity" the "high power mode" may be more advantageous. Apple says the feature is intended for "sustained" workloads.
High energy consumption mode can be enabled under "Battery" or "Energy" in the system settings app.