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.

(0-0) Peak Power

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.

The AMD Ryzen AI 9 HX 370 Review: Unleashing Zen 5 and RDNA 3.5 Into Notebooks Core-to-Core Latency
Comments Locked

72 Comments

View All Comments

  • Rudde - Sunday, July 28, 2024 - link

    The core-to-core latencies are disappointing. The Zen 4 apu has less than 21 ns worst case. Compare that to Zen 5+5c where you are lucky to get 21 ns at all. Most surprising to me is that threads within the same core have similar latency as between cores.

    I couldn't find any Zen 4+4c core-to-core latencies. The issue might have already been present in previous generation where Zen 4c wasn't used for the top-of-the-line.
  • haplo602 - Monday, July 29, 2024 - link

    I was wondering the same. The division between the 2 core clusters is clearly obvious and this will make OS scheduling a problem. But even in the high-perf cluster the latencies are way worse than Zen4 ... also the fact that threads on the same core have the same latency as threads on different cores within the same cluster is unusual ... there seems to be some cache issue ...
  • bernstein - Sunday, July 28, 2024 - link

    wait wtf? rdna3.5 looks way faster than rdna3 (7940HS):
    in cp2077 it's 69% faster
    in returnal it's 58% faster
    in warhammer 3 it's 44% faster
    sure that's with 33% more CU's but then again, it's at lower power (28W vs 35W)

    i didn't expect too much of strix halo, but with rdna3.5 this efficient it will undoubtedly make a real splash when it hits with ~2.5x this perf at ~70W
  • haplo602 - Monday, July 29, 2024 - link

    the new ryzen is running with lpddr5 7500MT/s which helps the graphics. if the 7940HS model is on 5600MT/s so-dimms then that's a huge difference right there ....
  • Khanan - Monday, July 29, 2024 - link

    - better cores, arch is slightly upgraded
    - more cores 256 shaders more (1024 total), which now reached a respectable number that is 4 digits like a discrete gpu card
    - better vram and thus more bandwidth which also helps with performance like the other guy mentioned.
  • dwade123 - Sunday, July 28, 2024 - link

    Wow this looks utterly disappointing. AMD's last chance to grab some mobile marketshare goes out the window. I won't be surprised if we see Lunar Lake taking over even the niche PC handheld marrket... ouch!
  • abufrejoval - Monday, July 29, 2024 - link

    Do you at least get paid for comments like this?
  • Khanan - Monday, July 29, 2024 - link

    No i think he lacks the knowledge to understand the review.
  • TheinsanegamerN - Wednesday, July 31, 2024 - link

    This is your brain on Intel Rap- *blue screen*
  • Duncan Macdonald - Monday, July 29, 2024 - link

    Could you run at least one of the tests at the 4 different power levels that this laptop supports to show the impact of power on performance.

Log in

Don't have an account? Sign up now