Testing laptops on battery and AC power — Comparing Intel, Qualcomm, Apple, and AMD
Do you get the same performance on a plug and on battery? Sometimes!
When you use a laptop, you might assume that it will always perform the same, whether you use it while plugged in or unplugged. After all, these systems are designed to be used on the go. But for a long time, that hasn't been the case.
More recently, some silicon vendors have been boasting about closer parity in plugged and unplugged performance, offering you similar power whether you're working at your desk or anywhere else. To see the current state of this, we've taken samples of the latest laptop from each major CPU manufacturer: Intel, AMD, Qualcomm, and Apple, and run a few tests to see how they compare.
For the Windows systems, we used the balanced power profile, which was already the default on the majority of these laptops, while the MacBook Pro has an "automatic" power management profile out of the box.
Where we could, we went for top-end processors, including the Intel Core Ultra X9 388H, Qualcomm Snapdragon X2 Elite Extreme, and Apple's M5 Max. In AMD's case, we had two Gorgon Point processors, a Ryzen AI 9 465 and a Ryzen AI 7 445. To see some generational gains, we also included an Intel Core Ultra 7 258V "Lunar Lake" chip.
We tested three ways: in Cinebench 2026 single-core and multi-core workloads, as well as using Handbrake, an open source video conversion tool, to transcode a 4K video to 1080p.
Note that we're not comparing the scores of the systems to each other. We're comparing the systems to themselves, to see how performance changes on the battery.
With those tests run, we can calculate percentage differences to see percentage changes. Notably, a number of systems actually increased performance ever so slightly on battery. This occurred the most on multi-threaded Cinebench, where the Zenbook A16 with Snapdragon X2 Elite Extreme increased by 13.06%, while the ThinkPad X9 bumped up by 4.98%.
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| Row 0 - Cell 0 | Asus Zenbook Duo (Intel Core Ultra X9 388H) |
Asus Zenbook A16 (Snapdragon X2 Elite Extreme) |
Apple MacBook Pro (14-inch, M5 Max) |
Acer Swift Go 16 AI (AMD Ryzen AI 7 445) |
Average |
+0.01% |
-0.41% |
+0.08% |
-50.06% |
Cinebench 2026 (Single-threaded) |
0% |
-0.96% |
+0.27% |
-56.25% |
Cinebench 2026 (Multi-threaded) |
-3.41% |
+13.06% |
+0.85% |
-42.28% |
Handbrake |
+3.43% |
-13.33% |
-0.89% |
-51.64% |
Qualcomm's chip was by far the most variable. While it dramatically increased in performance on battery for Cinebench nT, it dropped a similar amount for Handbrake.
But it was Apple and Intel that led the pack. While the Core Ultra X9 388H had the most consistent score on average, it did show 3% swings in multi-threaded Cinebench and on Handbrake. Apple's M5 Max results were the most consistent throughout, never swaying even a full percentage point on battery.
The least consistent system on battery power was the Acer Swift Go 16 AI, running on an AMD Ryzen AI 7 445. That system lost a ton of performance when unplugged from the wall, dropping as much as 56.25% performance off the wall. On average, benchmark scores were 50% lower on that system. On the HP OmniBook X Flip 14, Ryzen AI 9 465, it still dropped, but far less, losing an average of 5.45% performance on power based on these tests.
On the bright side, things are going in the right direction. Intel and Apple's most advanced systems give you very similar experiences on battery and power — at least in these tests. Snapdragon can, but sometimes it swings a bit. It's really AMD that needs to catch up in this regard. And we know that can be done. The Steam Deck, which was released in 2022, was specifically designed to have similar performance on and off the charger, and it uses a semi-custom AMD SoC. Its AMD-based opponents, however, still get better performance on a charge. You not only have to have your chip designed around battery and performance. You also need to make sure that the system around it is optimized for that.
The other side of this coin is efficiency. If you're able to perform heavy tasks on battery without losing performance, you're likely going to do it. That's especially the case if you do field work in creative or industrial fields. That means ensuring that your system can handle your workload long enough to get it done. But hey, there's always an external battery, right?

Andrew E. Freedman is a senior editor at Tom's Hardware focusing on laptops, desktops and gaming. He also keeps up with the latest news. A lover of all things gaming and tech, his previous work has shown up in Tom's Guide, Laptop Mag, Kotaku, PCMag and Complex, among others. Follow him on Threads @FreedmanAE and BlueSky @andrewfreedman.net. You can send him tips on Signal: andrewfreedman.01
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NinoPino Not a good test for the following reasons :Reply
Tested only 2 applications (Cinebench and Handbrake)
Forcing a native multithreaded application (Cinebench) to work in single thread mode to benchmark a system is a nonsense. In no real scenario this application will be used this way.
Cinebench was used two times to do the mean, so it makes the situation worst, giving the mean a strong bias on Cinebench use
In the conclusions you talk of the CPU results, not of the system results. This is not a CPU plugged/unplugged test, but a 6 laptop test. In no way this test can be significant of CPUs unpugged performance.If we exclude the totally irrealistic Cinebench single thread scenario, we obtain a little different picture :
Zenbook Duo (Core U X9 388H) from 0% to -3.4%
Zenbook A16 (Snapdragon X2 E E) from -0.4% to 0%
Macbook Pro stay 0%
Acer Swift Go 16 AI (Ryzen AI 7 445) from -50% to -46%
Omnibook X Flip 14 (Ryzen AI 9 465) from -5% to -0.5%
Thinkpad X9 (Core U 7 258V) from +1.4% to 0.65%
In the conclusions you write that "... it was Apple and Intel that led the pack". But if we look at the average score without the single thread test, essentially we have all the system scoring in the same way, because the Acer Swift is clearly an exception. -
salgado18 This is so superficial that it doesn't even seem like Tom's. Three benches, only performance numbers of CPU, and that's it. How much does the estimate battery drop during tests? How much battery is used after 15 minutes of stress tests? What about GPU? Other power profiles?Reply
We want more answers, not more questions! Intel probably drains battery like a monster to keep performance high, while AMD drops a little to keep you using the computer for longer. Apple seems to be the efficiency king - is it?
Sorry, really disappointed at the wasted opportunity. I want these tests, but in-depth, not just a quick bench run on a fancy graph. -
thestryker While I get the aim of this testing it really needed a few more tests to be run. At least 2 ST, 2 MT and 2 mixed to really get an idea as to what the performance behavior looks like and we only got 1 ST and 2 MT. I'm not looking for a full review or battery life testing, but there simply isn't enough here to make any real. conclusions beyond what we already knew: since LNL Intel has been looking at Apple for performance intent.Reply -
wussupi83 Interesting results. I love these types of articles. I've used a 258v in a HP Omnibook. On battery power it doesn't leave PL1 but when plugged in it goes to PL2. So I imagine the results would look different than the Lenovo.Reply