System Performance

To test Intel's Atom Z3580 SoC I've run the phone through our standard suite of benchmarks. These tests range from browser tests that test the speed of the SoC and the browser's Javascript engine, to more native tests like writing text and seeking through videos. Even some tasks that seem simple can be quite demanding on devices where the entire system is limited to a power envelope of around 3W. Luckily, the ZenFone 2 runs Android Lollipop and so it's using Google's new ART runtime for Java based Android applications. However, even ART is limited in what it can do, as AOT compiler optimizations are limited by a need to balance the CPU's limited power with the need to compile apps quick enough that the user isn't stuck waiting long after they are downloaded.

Although it's a bit unfair as it's a tablet, I've included Dell's Venue 8 7000 in these results because it uses the same SoC as the ZenFone 2 and so it makes for an interesting comparison.

As usual, the first tests that I'll be looking at are our browser benchmarks. Sunspider had become such a large optimization target that it's basically gone from our 2015 benchmark suite, which leaves us with Kraken, Octane, and WebXPRT 2013.

Kraken 1.1 (Chrome/Safari/IE)

Google Octane v2  (Chrome/Safari/IE)

WebXPRT (Chrome/Safari/IE)

In our web browsing tests the ZenFone 2 performs very well. In the case of Kraken, it does roughly as well as the Venue 8 7000 which uses the same Z3580 SoC. Performance tends to fall behind the Venue 8 in our longer tests like Octane and WebXPRT. I don't have the Venue 8 anymore, but it's a safe bet that this is due to the larger aluminum chassis of the Venue 8 being able to manage heat better in order to keep the clock speeds on the CPU higher during the course of the test.

While the ZenFone 2 isn't quite as fast as a tablet using the same SoC, it's much faster than most of the other devices that we've tested. In general it ends up being a bit slower than the iPhone 5s and the iPhone 6, and of course it loses to the Galaxy S6 using Samsung's browser by an enormous margin in every case. However, a good portion the phones that sit below it are very expensive flagship phones like the Nexus 6, LG G3, and the Galaxy Note 4 which is very impressive for a $300 smartphone.

The next test is Basemark OS II which tests the performance of a device's CPU, GPU, RAM, and NAND.

Basemark OS II 2.0 - System

The system sub test performs integer and floating point operations, and also performs some tests like XML parsing. This makes it primarily a test of the device's CPU and RAM. I'm actually somewhat surprised by the ZenFone's performance in this test. By no means is it bad, but I had forgotten that the Venue 8 also struggled to match Snapdragon 801 smartphones in this test.

Basemark OS II 2.0 - Memory

The Basemark OS II memory sub test has a somewhat vague name. While one might expect it to be a test of the device’s RAM, it’s actually a flash storage test. In it we see one of the highest scores of the smartphones we’ve tested, with only the Dell Venue 8 tablet and the Galaxy S6 with its UFS memory achieving higher scores.

Basemark OS II 2.0 - Graphics

The result in the graphics test is definitely on the lower end of our results, but it’s not unexpected. Both the Venue 8 7000 and the iPhone 5s achieve similar scores, and all three devices use the same G6430 GPU (albeit with lower clock speeds on the iPhone). Even though the ZenFone 2 doesn’t perform as well as the expensive flagship smartphones, it’s far ahead of budget devices like the Moto G. Since both the Z3560 and Z3580 based ZenFone 2 models use the same 533MHz PowerVR G6430 this result should be roughly the same on the $199 model as it is on this $299 model.

Basemark OS II 2.0 - Web

The last sub test is the web test. This test focuses on a device’s ability to handle web page rendering, with a focus on HTML5 and CSS rather than Javascript code. In this test we see the ZenFone 2 amongst a large group of devices that includes the HTC One (M9), the Nexus 6, and the Moto X. To see the same level of performance as Snapdragon 805 and 810 devices is very impressive.

Basemark OS II 2.0 - Overall

The overall score for BaseMark OS II takes into the account the scores of the various sub tests to generate a final score. In this test we again see the ZenFone 2 around the middle of the pack, with a score that is similar to that of Snapdragon 801 based devices. This is a very good result for a smartphone that costs so little, although the OnePlus One also achieves similar performance at roughly the same price as the $299 model of the ZenFone we are testing.

Our last general performance benchmark is PCMark. This is a relatively new addition to our testing workflow, and it focuses on race to sleep scenarios that reflect the type of usage a device will see in the real world. The tests range from Javascript performance, to playing and seeking in videos, to editing photos.

PCMark - Web Browsing

PCMark - Video Playback

PCMark - Writing

PCMark - Photo Editing

PCMark - Work Performance Overall

In all of the PCMark sub tests the ZenFone 2 performs extremely well. It’s always at or very close to the top result, and only really loses by a large margin to the Galaxy S6 in the tests that it isn’t right near the top for. The one exception is the photo editing test where it beats every other device by an enormous amount. This score is what carries it to the top position when it comes to the overall score.

I think it’s a bit unfair to say that the ZenFone is the fastest device when it only comes first in a single test, but even without considering the photo editing test it’s clear that the ZenFone 2 offers great performance. Even more amazing is that at times it can trade blows with flagship phones that cost much more than it does. Perhaps due to the fact that it's the only x86 Silvermont-based phone in our benchmarks its relative performance can bounce around versus the competition, but on average it comes rather close to delivering the kind of CPU performance we've seen from the flagship phones over the past year.

Battery Life and Charge Time System Performance Cont'd: GPU Performance


View All Comments

  • Brandon Chester - Tuesday, May 26, 2015 - link

    Google Chrome is used for all of our browser tests, including battery life. Reply
  • re2onance - Tuesday, May 26, 2015 - link

    I remember watching a review earlier about the screen being low in brightness. I thought it may have been on purpose although I assumed it was due to Asus trying to make up for the Intel SoC power consumption.

    I've read in the XDA forums that people experience better battery life after rooting and removing a lot of the bloatware apps, particularly the Asus built-in web browser that seems to be attached to the Trend Micro security. Honestly, people shouldn't have to root their device in order to eek out better battery life.

    It seems kinda weird how Asus would spend the effort to gimp the screen from what it is actually capable of, and then fill it with apps which probably also could hinder battery life as well.
    It seems like a good value phone, but the direction is all over the place.

    I think the review seems fair since this is both the hardware and software Asus shipped with and updated.
  • T1beriu - Tuesday, May 26, 2015 - link

    Brandon, could you actually disable all ASUS bloatware?

    I got an ASUS MeMO Pad 7 (ME572C) updated to 5.0 that looks exactly as your screenshots and I can't disable any of the useless ASUS apps.

    Shame on you ASUS.
  • Brandon Chester - Tuesday, May 26, 2015 - link

    No you can't disable all of it. I probably should have been more specific about that. You can uninstall or disable some apps such as the Apps4U apps and a few others like Omlet chat. Most of the apps that are actually from ASUS are stuck there though. Reply
  • ketacdx - Tuesday, May 26, 2015 - link

    Hey Brandon. I thought the same but if you follow the method of holding the app in the app menu and drag it to uninstall at the top, that seems to work for most. For some reason I wasn't able to uninstall in Google Play for the same ones oddly, only disable. Reply
  • Brandon Chester - Wednesday, May 27, 2015 - link

    That isn't working for me for apps like ZenCircle, Mirror, etc. The button to disable is greyed out. Reply
  • ketacdx - Thursday, May 28, 2015 - link

    Yeah, I cant get those off either but it worked a lot of them thankfully. I really wish they enabled uninstall for the rest... Reply
  • tipoo - Tuesday, May 26, 2015 - link

    "In the case of the ZenFone 2, we see that it lasts exactly as long as the HTC One (M9). Last run GPU performance is noticeably slower though."

    But isn't that just the relative performance difference between the two GPUs? I guess I still don't really understand the last run GPU framerate metric, shouldn't it be as a proportion of the first run framerate to mean anything? If one device performs at 100, another performs at 50, and the final runs of both are 50, the final run FPS would appear the same, but the second device didn't throttle at all while the first throttled by half.

    Does the test already take this into account?
  • SHartman1976 - Tuesday, May 26, 2015 - link

    I think you guys need to rerun the Nexus 6 battery benchmarks with 5.1 - the experience of myself and many others regarding N6 battery life is nothing like what you found on the initial 5.0 review. Reply
  • Brandon Chester - Wednesday, May 27, 2015 - link

    I just finished re-testing the Nexus 6 on 5.1 and it lasted for 7 hours and 24 minutes in our browser test which is a worse result than the initial review. It's a small enough difference that I'll attribute it to battery degradation and/or test variance, but the point is that it hasn't improved at all. Reply

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