The AMD Ryzen AI 9 HX 370 Review: Unleashing Zen 5 and RDNA 3.5 Into Notebooks

ASUS Zenbook S 16: Power Consumption & Performance Modes

A big part of any laptop's performance is its TDP – how much energy the chassis can consistently dissipate – meaning that two laptops can have wildly different performance, despite using the same chip, just by virtue of their cooling capabilities. So measuring the peak and sustained power consumed by a laptop is particularly important, both to get an idea of where it falls on the ultrabook-to-DTR spectrum, but also how a design compares to other laptops. Especially with an architecture launch like this one, we need to know if a performance lead comes from architecture and efficiency, or just running a lot of power through a chip.

The AMD Ryzen AI 9 HX 370 has a rather large configurable TDP range overall, with the chip capable of being set to anything between 15 and 54 W. This gives Strix Point a wide berth to fit in everything from ultrabooks to larger gaming notebooks, but it also means that the chip's performance, particularly in heavily multi-threaded and mixed CPU/GPU workloads is going to be defined by its TDP.

Despite its 16-inch frame, In the ASUS Zenbook S 16 is configured rather conservatively. ASUS has taken what's nominally a 28W chip and dialed it down to 17W for it's out-of-the-box experience. Dubbed "Standard Mode" the out-of-the-box experience is a laptop that's highly efficient and highly quiet, but does leave some performance on the table for the sake of acoustics.

ASUS also gives the user quite a bit of latitude to pick performance modes here, with the Zenbook offering 4 different modes altogether. Besides the standard mode, there's the ultra quiet "Whisper mode", the performant "Performance Mode" with a 28W TDP, and the no-holds-barred "Full-speed Mode".

For most of the Zenbook S 16 you'll see today – ours included – you'll find these laptops are running in the 28 Watt Performance Mode. This comes by request of AMD, who is looking to show off what the chip can do at its standard TDP, rather than ASUS's dialed-down TDP. And while we're not beholden to this (or any other) request from AMD, from a pragmatic standpoint it's a lot easier to find 28W laptops than it is 17W laptops. So for our first round of testing, we have dialed up our laptop to its 28W mode.

In our peak power test, the Ryzen AI 9 HX 370 ramped up and peaked at 33 W. We typically see a higher peak power value than the TDP before things settle down during an intensive workload, although the Intel Core Ultra 7 155H within the ASUS Zenbook 14 OLED did manage to peak at 64 W for a very brief moment, which is way out of spec.

Looking at the power of the Ryzen AI 9 HX 370 when using Maxon's latest Cinebench 2024 (multi-threaded test) benchmark, which is quite an intensive rendering workload, we can see how it compares to the Ryzen 9 7940HS when dialed down to 35W, as well as the Intel Core Ultra 7 155H which is running at 28W within the ASUS Zenbook 14 OLED. Aside from the very large spike up to 45W on the Core Ultra 7 155H, we see a pretty consistent level of power usage from the CPU package (the cores).

Focusing on the Ryzen AI 9 HX 370, we can see it quickly ramped up and achieved a very consistent load level, bouncing between 32 and 33 W throughout the Cinebench 2024 MT benchmark loop. As the benchmarking loop carried on, power consumption slowly dropped to a steady-state TDP of 28W, matching the configured TDP of the laptop. The slow and gradual drop in power towards the end was very smooth. The same can be said about the Ryzen 9 7940HS. In contrast, the Intel Core Ultra 7 155H produces some slightly noisier data, bouncing around between 26.5 W and 29 W throughout the test.