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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name99 - Saturday, October 6, 2018 - link
If you're going to count like that, you need to throw in at least 7 Chinook cores (small 64-bit Apple-designed cores that act as controllers for various large blocks like the GPU or NPU).[A Chinook is a type of non-Vortex wind, just like a Zephyr, Tempest, or Mistral...]
There's nothing that screams their existence on the die shots, but what little we know about them has been established by looking at the OS binaries for the new iPhones. Presumably if they really are minimal and require little to no L2 and smaller L1s (ie regular memory structures that are more easily visible), they could look like pretty much any of that vast sea of unexplained territory on the die.
It's unclear what these do today apart from the obvious tasks like initialization and power tracking. (On the GPU it handles thread scheduling.)
Even more interesting is what Apple's long term game here is? To move as much of the OS as possible off the main cores onto these auxiliary cores (and so the wheel of reincarnation spins back to System/360 Channel Controllers?) For example (in principle...) you could run the file system stack on the flash controller, or the network on a controller living near the radio basebands, and have the OS communicate with them at a much more abstract level.
Does this make sense for power, performance, or security reasons? Not a clue! But in a world where transistors are cheap, I'm glad to see Apple slowly rethinking OS and system design decisions that were basically made in the early 1970s, and that we've stuck with ever since then regardless of tech changes.
ex2bot - Sunday, October 7, 2018 - link
Much appreciate the review!s.yu - Monday, October 8, 2018 - link
Great job as always Andrei!I would only have hoped for a more thorough exploration of the limits of the portrait mode, to see if Apple really makes proper use of the depth map, taking a photo in portrait mode in a tunnel to see if the amount of blur is applied according to distance for example.
Mic_whos_right - Tuesday, October 9, 2018 - link
Thanks for this comment--Now I know why nothing last year. Great Anandtech standard of a review! Always above my intellect of understanding w/ info overload that teaches me a lot of the product.Moh Qadee - Thursday, November 1, 2018 - link
Thank you for this great detailed review. I have been coming back to this review before making a purchase. Please make an comparison article of Iphone XS gaming vs other smartphones in market. How much does thermal make difference over longer periods before it starts to throttle or heat up. Would be able to give an approx time before you noticed heat while gaming on XS? I don't mind investing in an expensive phone as long as thermals doesn't limit the performance. There are phones like Razor 2 or Rog out. People make an comparison with an iPhone as it doesn't require much cooling. I wonder if gaming for above 20+ mins makes it challenging for Iphone to heat up enough that you should be worried about?Ahadjisavvas - Monday, November 19, 2018 - link
And the exynos m3 had 12 execution ports right? Can you elaborate on the major differences between the design of the vortex core in the a12 and the meerkat core in the m3? I would deeply appreciate it if you could.Ahadjisavvas - Monday, November 19, 2018 - link
And the exynos m3 has 12 execution ports right? Can you elaborate on the main differences between the design of the exynos m3 and the vortex core,that'll be really helpful and informative as well. Also,are you planning on writing a piece about the a12x soc, it'll be really interesting to hear how far apple has come with the soc on the 2018 ipad pro.alysdexia - Monday, May 13, 2019 - link
"Now what is very interesting here is that this essentially looks identical to Apple’s Swift microarchitecture from Apple's A6 SoC."This comparison doesn't make sense and it seems like you took the same execution ports to determine whether the chips are identical, when the ports could be arbitrary for each release. Rather I took the specifications (feature size, revision) and dates of each from these pages: https://en.wikipedia.org/wiki/Comparison_of_ARMv7-... and https://en.wikipedia.org/wiki/Comparison_of_ARMv8-... to come up with these matches: Cortex-A15-A9 A6, Cortex-A15-A9 A6X, Cortex-A57-A53 A7, Cortex-A57-A53 A8, Cortex-A57-A53 A8X, Cortex-A57-A53 A9, Cortex-A57-A53 A9X, Cortex-A73 A10, Cortex-A73 A10X, Cortex-A75 A11, Cortex-A76 A12, Cortex-A76 A12X. For exemplum 5 execution ports could be gotten (I'm no computer engineer so this is a SWAG.) from the 3 in Cortex-A9 subtracted from the 8 in Cortex-A15 but the later big.LITTLEs with 9 and 5 ports could be split from 7 or 8 as (7+2)+(7−2) or (8+1)+(8−3). You need to correct the Anandtech and Wikipedia pages.
faster -> swifter, swiftlier
ISO -> iso -> idem
's !-> they; 1 != 2
great:small::big:lite::mickel:littel
RSAUser - Friday, October 5, 2018 - link
I still don't like iOS tendency towards warmer photos than it is irl.DERSS - Saturday, October 6, 2018 - link
It is weird because it is warmer in bright light and bleaker in dim light.Why can not they just even it out, make the photos less yellowish in bright light and less bleak in dim light?