One of the biggest worries that people have about quad-core processors is that they are power-hungry. NVIDIA even went as far as adding a fifth CPU core - a so-called power-saving core - to improve battery life.
Manufacturers have also tried shoving large batteries inside the phones. With the extra room from the large screens, they've had some success - the LG Optimus 4X HD and the Samsung Galaxy S III have 2150mAh and 2100mAh batteries respectively. The HTC One X has "only" 1800mAh in its battery, despite its size, and the Meizu MX 4-core comes very close to it despite more compact.
If you haven't read them, we have blog posts with detail on the battery life on each phone individually (you can find the links at the bottom of each phone's specs table). Here we'll concentrate on comparing the battery performance of the four phones.
Let's start with the final reading - our endurance rating. It measures how long a phone can last given a predefined usage pattern. We use an hour of talk time on a 3G network, an hour of web browsing over Wi-Fi and an hour of watching an SD video every 24 hours.
The Samsung Galaxy S III scores the highest here with 43 hours - if your usage isn't heavier than our test usage, it will get you through almost two full days before you need to hook it up to a charger.
The other phone with a large battery - the LG Optimus 4X HD - comes in second with a 40 hour score. Depending on how late you come back home on the second, it might too get you through two days of usage.
The HTC One X and Meizu MX 4-core and their smaller batteries last around 37-38 hours of usage, which is closer to a day and a half.
Let's look at how the phones handle each individual task. The LG Optimus 4X HD runs out of juice in under 8 hours of talk time, while you can get about 10 hours of the other three.
The Optimus and the HTC One X show an unimpressive web browsing time of about 4 hours before their batteries run flat - surprisingly the Galaxy S III beats them by an hour (phones with AMOLED screens typically don't do too well when faced with the predominantly white web pages in our our web browsing test) as does the Meizu MX 4-core (though the smaller screen on this one surely helps).
The Samsung Galaxy S III takes the video watching championship by a huge margin - more than double of what the worst performer of the four phones (the Optimus 4X HD) achieved.
The Samsung Galaxy S III offers the best battery life of the four and people who spend a lot of time watching videos on their phone will really feel the difference.
Next comes the LG Optimus 4X HD - it scored the lowest in the three categories (talk time, browsing and videos) and it's only that power-saving fifth core, enables efficient standby, that helps it save face. It good a good overall score, but given that it has the biggest battery we really expected it to do even better.
A part of the explanation is that the LG Optimus 4X screen is much brighter when set to 50% than its three competitors, which means that it needs more power to work. However, it's not just that as repeating the tests at automatic brightness returned quite similar results and the screen doesn't even work during the talk time test.
The LG Optimus 4X HD and the Samsung Galaxy S III also deserve extra points for allowing you to replace their batteries and giving you the option to carry a spare one when you need extra endurance.
The Meizu MX 4-core would be our third pick - it can't match the S III when it comes to watching videos, but it does match it in the other two categories. Its inefficient standby costs it a few hours off the endurance rating, though. It will probably do better than the Optimus 4X HD when used more heavily, but its non-replaceable battery relegated it to third place.
The HTC One X will let you talk for a long time, but when it comes to browsing the web or watching videos it's only average. Shame that HTC didn't fit a bigger battery (it's non-replaceable too).