The iPhone XS & XS Max Review: Unveiling the Silicon Secrets
by Andrei Frumusanu on October 5, 2018 8:00 AM EST- Posted in
- Mobile
- Apple
- Smartphones
- iPhone XS
- iPhone XS Max
Battery Life
The iPhone XS comes with a 2658mAh/10.13Wh battery, while the XS Max has a capacity of 3174mAh/12.08Wh. Again, it’s to be noted that although both phones are quite large form-factor devices by now, Apple’s battery density still largely lags behind the competition. While yes, it’s true that the XS Max’ battery is the biggest that Apple has ever used, it still pales in comparison to the 3500 to 4000mAh that other vendors now employ in the same form-factor.
As we saw in the SPEC analysis, the one advantage that Apple has is an enormous lead in terms of power efficiency of its SoC, which largely makes up for any gap in the battery capacity deficit.
Our web browsing test is a mixed-to-heavy workload that iterates through a set of popular webpages that are hosted on our server. The test loads a web page, pauses, scrolls through it, pauses, and then continues to the next in the set, repeating all over when done. Brightness is fixed at 200cd/m².
The iPhone XS saw a very slight degradation compared to the iPhone X in our test. The 19 minute deficit isn’t terrible, but it does come at a surprise given that Apple had promised improved battery life for the new model. What’s happening is that likely our test is a tad heavier in its workload than what Apple and many other vendors internally test to advertise as the daily battery life of their devices.
The iPhone XS Max came in at 10.3h. Again while this is still good, it’s a degradation over the 11.83h of the iPhone 8 Plus. Here it’s easier to rationalise the difference; the OLED screen of the XS Max is just more power hungry and also has a larger area than the iPhone 8 Plus. Here the increased battery capacity isn’t enough to counteract the panel’s increased needs.
As to why the iPhone XS saw a degradation over the X, I’m not too sure. I did rerun the test on the iPhone X to make sure iOS12 hadn’t impacted the devices – and I got a runtime just 10 minutes lower than what I had tested on the iPhone X back around in January, so the iOS upgrade certainly doesn’t seem to have affected the battery life.
It should be relatively safe to assume that the new A12 should be more efficient in its workloads, even with the increased performance that it brings. One thing that we can’t really verify is the power efficiency at intermediate performance states, as that’s also where CPUs perform a lot of their work at.
We also have to keep in mind the connectivity factor: the new iPhone’s seems to sport a new Broadcom BCM4377 WiFi combo chip which we don’t know much about. Most importantly the new XS have also switched over from a Qualcomm baseband (in our test unit of the iPhone X) to a new Intel XMM7560 baseband.
I’ve generally given up on LTE testing after a few years ago I had run into some serious issues regarding a misconfiguration of my mobile carriers’ baseband stations as they did not have CDRX enabled. This caused an almost 20-30% battery life degradation on Huawei’s devices – and if I hadn’t debugged the issue with HiSilicon I’d probably be none the wiser. Fact is, cellular battery life testing is a lot harder than one would think, and without having a controlled environment, I’m very hesitant to resume cellular battery life testing.
That being said, I will revisit the iPhone X vs iPhone XS battery life topic while on LTE over the weekend and post an update to the review.
Overall, the battery life of the iPhone XS and XS Max are good – they don’t quite reach Apple’s claimed improvements, but that also just might be something that will vary from use-case to use-case.
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Constructor - Monday, October 8, 2018 - link
I don't see that happening at all because Apple has explicitly maintained a clear distinction between Macs and iOS exactly along the lines of different interaction paradigms (point-based vs. touch).Windows with touch continues to be a mess and I don't see Apple following Microsoft into that dead end.
Constructor - Monday, October 8, 2018 - link
If they'd have a replacement offering noticeably higher performance than any Intel Mac Pro and if legacy software at least ran decently until new ARM recompiles were available, I don't think most users would mind all that much.Going from PowerMacs to Mac Pros was also not entirely painless, but most users still thought it was worth it overall.
id4andrei - Sunday, October 7, 2018 - link
Andrei, I remember you mentioning in the comment sections of an article - maybe the S9 review - that the A11 cannot maintain it's freq and drops by as much as 40% while the Snapdragon drops only 10% on sustained workloads.You made your testing on a bench fan. You tested the potential of the A12, and it is incredible, but not the real life performance of the iphone. When used for prolonged sessions the A12 might reach its threshold faster than the Snapdragon and drop performance. What are your musings on this? Throttling matters and identifying it is very important, especially considering Apple's recent history. The CPU is great but is that top performance sustainable and for how long?
Andrei Frumusanu - Sunday, October 7, 2018 - link
What you mention is in regards to the GPU performance, it's addressed in that section in this piece.And of course it's the real performance of a phone. The duration of a benchmark doesn't change the fact that the CPU is capable of that throughput. Real world workloads are transactional and are a few seconds at best in the majority of use-cases. In such scenarios, the performance is well exhibited.
id4andrei - Sunday, October 7, 2018 - link
That makes perfect sense. No one does folding on smartphones. Thanks for the prompt reply.eastcoast_pete - Sunday, October 7, 2018 - link
Also, folding your smartphone is really hard, and doesn't end well for the phone (:FunBunny2 - Sunday, October 7, 2018 - link
"folding your smartphone is really hard, and doesn't end well for the phone"I don't recall (too lazy to confirm :) ) which company, but a patent was awarded a couple or so years ago for a flexible display, such that it would (according to the drawing I saw) make a cylindrical bend the hinge when closed. still hasn't appeared, so far as I know. let's see... looks like Samsung and LG have some, and more recently than when I first saw..
here: https://www.androidauthority.com/lg-foldable-phone...
eastcoast_pete - Monday, October 8, 2018 - link
Yes, that comment was in jest. I believe both Samsung, LG and Huawei have folding smartphones with folding screens underdevelopment. If those work out and aren't too pricey, I'd be interested. Nice to be able to fold a phone with a 7 inch display to a little more then half its full size.varase - Tuesday, October 23, 2018 - link
While this would probably be neat to see in the short run, I can't imagine that would yield a long lasting display over the long haul.Javert89 - Sunday, October 7, 2018 - link
Hi, do you think the current power draw of the CPU (in watt) is sustainable for the battery, expecially in the long term? In this review you cite a case where a GPU benchmark made crash the phone because the power required is too high.. Any chance to see this behavior on real life scenario? Moreover do you think that the power draw (watt) is sustainable in smartphone envelope? Or other aspects like overall power consumption or leakage count?