Asus Zenfone 2 Review : World's First Smartphone with 4GB RAM

A few weeks ago, Asus launched world's first 4GB RAM smartphone, Asus Zenfone 2 which became an instant hit in the Indian market. Asus Zenfone 2 was launched in four different variants with different storage options, slightly different specifications & price tags, out of which, one of them houses 2GB RAM, while the others pack 4GB RAM. If you are a regular visitor of this blog then you must have read my previous article '6 Reasons Why You Should Wait for Asus Zenfone 2' In which I laid down some reasons explaining why Asus Zenfone 2 is worth to wait for, if you haven't read it then go ahead and take a look at it. Recently, I got the opportunity to review Asus Zenfone 2 (ZE551ML) and here I am sharing my experience. 



The box is pretty standard & compact. On opening the box you'll find the Asus Zenfone 2 resting inside, under which you'll find the accessories. The accessories which come with Zenfone 2 are pretty basic, no earphones were found inside the box, all it had was a Charging Adapter, a USB to MicroUSB cable and a few booklets with warranty card and that's all. When unboxing the device, I was hoping to find earphones inside but 

Built Quality & Looks

Looks were the thing which impressed me as soon as I took the device out of the box. The phone is quite large but still easy to hold in one hand, though I think one-hand operation is still not possible. The Back looks amazing with the texture and metal like appearance (Please Note the back is made of plastic) the power button and the volume rockers are placed at odd places and I didn't like that because I'm used to the standard placement, the power key now is placed at the top and the volume rockers are on the back, under the camera. 


The back panel is removable but the battery is not, under the back panel you'll find Dual-SIM slots and microSD card slot. when I was using the device, I found that the back panel is a bit tough remove and in worst cases can break when attempting to remove, this is because when we pull it, some of the locks still stay in place and if the material bends more than it supposed to, it can break, so be careful when opening the back panel. The top has 3.5 mm jack next to the power button. The back itself has speaker grill and Intel branding. Overall the build quality is sturdy and nice.

Display & Audio

Asus Zenfone 2 packs a 5.5" Inch Full HD IPS Display with the resolution of 1920 x 1080 pixels and pixel density of ~403 ppi. The Display comes with Corning Gorilla Glass 3 protection which prevents the display from accidental scratches. The display of  Zenfone 2 is bright and looks great, the sunlight legibility is good but not as I expected it to be, Xiaomi Mi4 is much better when it comes to sunlight legibility, but still you can clearly see the display of Asus Zenfone 2 pretty well in sunlight. Overall the display of Asus Zenfone 2 is good and will make it difficult for you to take your eyes off of it. 


The loud speaker on Asus Zenfone 2 is located on the back. During our tests, we found that the speakers weren't loud enough, in case your phone is resting on it's back and the speakers are covered, you might not be able to hear the ringtone. When earphones are connected, Asus Zenfone 2 works great and produces quality sound, the music experience on Asus Zenfone 2 with earphones on is amazing.

Hardware & Performance

Asus Zenfone 2 packs a lot of power under the hood, it's been advertised as the world's first phone with 4GB RAM which is a big number for a smartphone in this range. The 4GB RAM variant of Zenfone 2 packs Intel Atom Z3580 chipset clocked at 2.3GHz Quad-Core, the 2GB RAM variant packs Intel Atom Z3560 chip clocked at 1.8GHz Quad-core. Both the variants has PowerVR G6430 GPU. The performance of Zenfone 2 is amazing, thanks to the high-end hardware and of course 4GB RAM, but I personally think the 4GB RAM is most of the time useless as a big part of it will always remain unoccupied, it's difficult to make use of full 4GB RAM, so it's not something for which you should upgrade, having it is great but if you are thinking of ditching your current 2GB/3GB RAM smartphone for 4GB RAM then think again. Asus Zenfone 2 really impressed me when it came to temperature, even after playing graphic heavy games for a decent time, there was no much increase in temperature, honestly saying I never found Zenfone 2 heating during my tests. Asus Zenfone 2 is available in 16GB/32GB/64GB models, it supports microSD card upto 64GB.

Asus Zenfone 2 has powerful hardware which performs well under all type of usage. The 4GB RAM is enough to house heavy activity and multitasks well. The CPU & GPU combination works great, delivering high performance when needed. 


Asus Zenfone 2 runs Android 5.0.2 Lollipop out-of-the-box, topped with ZenUI, which is a custom ROM from Asus. The ZenUI looks great but contains a lot of bloatware. The 4GB RAM helps in keeping the UI smooth & lag free. Since the ZenUI ROM is based on Lollipop, it has been customized with material design here and there. The Icons look pretty good with nice colors & shadows. ZenUI comes with a custom Keyboard which works well but there are a few languages which are not supported by ZenUI. The Keyboard comes in two different themes, one is dark and the other is light. The lock screen looks great, it has some shortcut buttons which will take you to Dialer app, camera and messages. Overall the ZenUI is nice for a change but I still prefer Google Launcher on Zenfone 2, as it makes the phone much faster & smooth as compared to the default launcher.


Asus Zenfone 2 has a 13 Megapixel camera on the back with two-toned LED Flash. The camera is capable of shooting Full HD videos at 30 fps. Other camera features include Auto-focus, Face detection, Panorama, HDR etc. There are a lot of other features & modes built in the camera app. 

The front camera is a 5 Megapixel shooter which can also shoot videos. The camera works really well and the photos clicked from the device are very details and produces accurate coloring, though the low light images are poor, even with the flash on. What I like about the camera is that you get 17 shooting modes to choose from, you can pick one according to the scene, the modes you get are Auto, Manual, HDR Beautification, Super resolution, Low Light, Night mode, Depth of Field, Selfie mode, GIF Animation, Panorama, Miniature, Time Rewind, Smart Remove, All smiles and Effects. You also get the option to shoot Panorama Selfie, which can accommodate a lot of people in a single selfie. The beautification mode helps in fixing your facial features by softening your skin & making it glow, you can also beautify your eyes, remove wrinkles and shape your chin. Auto mode works well if you don't know which mode to choose. Overall I was impressed with Zenfone 2 camera but the low light images captured were noisy and dull, other than that it was good.

Asus Zenfone 2 Sample shots | Video Test

Connectivity & Battery

Asus Zenfone 2 is a Dual-SIM smartphone and supports 2G, 3G & 4G Networks in India. The first SIM slot supports 2G, 3G & 4G SIM cards but the second slot only supports 2G networks. Other than this, Zenfone 2 has Bluetooth v4.0, Wi-Fi 802.11 a/b/g/n/ac, GPS with A-GPS and GLONASS, MicroUSB v2.0, TV Out support, Wi-Fi Direct, Hotspot, NFC, USB Host etc. It also has a FM receiver with RDS. Asus Zenfone 2 supports OTG connection.

Zenfone 2 houses a 3000 mAh Li-Polymer battery which is non-removable. Honestly saying, the battery life of Asus Zenfone 2 disappointed me, It barely lasted for a day with moderate use (with no gaming). With heavy multitasking, gaming and browsing, it lasted a half a day. i don't know whether it is a software fault or the battery is not optimized with hardware but for me, battery life was a big disappointment. I even tested the battery performance on 3 different Asus Zenfone 2 devices but the result was almost same which proves that my device wasn't at fault. I hope the next software update fixes the issue, otherwise you'll need to plug in a couple of times in a day, if you are a heavy user. Moderate users can pull off a day with Zenfone 2 if they follow Battery life saving tips. 


When testing Asus Zenfone 2, I was really excited to run benchmarks on it and see where the 4GB RAM takes it. Out of the several benchmarks we ran on it, below are the results of AnTuTu benchmark & Geekbench 3. 


On AnTuTu, Zenfone 2 got a score of 40916, while on Geekbench 3 it got a score of 2223 for multi-core and 918 for single core.


Asus Zenfone 2 is no doubt one of the best looking & performing smartphone in market in this price range., though I expected more from it, it still managed to impress me with its flawless design and high-end performance. I enjoyed testing the device, especially playing games on it. It also disappointed me in some areas like the battery life & low light photography, other than that, it is a great device. Also not to forget, the loud speaker of Zenfone 2 is not loud enough and sometime you'll have hard time listening to the ringtone, if the speaker is covered with something. Zenfone 2 is available in five different colors and two different variants. The available colors are; Osmium Black, Sheer Gold, Glacier Gray, Glamour Red and Ceramic White. 

I would totally recommend Asus Zenfone 2 4GB RAM variant to people who are more into gaming and multitasking, thanks to the 4GB RAM, the multitasking is flawless. However I will not recommend this to people who are looking for a device with long lasting battery, you can still buy this device if you carry along a Power Bank with you. I hope this review was helpful, please let me know about your experience with Asus Zenfone 2, in the comments section.


About Jimmie Luthra

Jim Luthra is a Third Officer in Merchant Navy and Chief Editor of, He is a Blogger, Guitarist, Painter, Book Lover, Tech Geek, Basket Ball Lover, Traveller and Fitness Freak. He loves Traveling and Adeventure Sports.
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