The LG Optimus 4X HD is the company's first quad-core device and it's the result of LG's continued collaboration with NVIDIA. The 4X HD uses the new Tegra 3 chipset with the so-called 4-PLUS-1 technology.
The Optimus 4X HD flaunts a gorgeous looking 4.7" True HD IPS screen (also known as HD-IPS). The high resolution means that the screen pulls off 300+ ppi pixel density (312ppi to be precise), despite its large size.
Speaking of size, the 4X HD felt smaller than the 2X. We didn't have a 2X at hand, but we got a definite feel of a more compact phone. We're not big fans of the back though.
Things get a whole lot better when you look under the hood. The LG Optimus 4X HD comes with a huge 2140 mAh battery. The number would have been even more impressive, had the battery used the standard 3.7V voltage, instead of 3.8V. The capacity gain over the Optimus 2X battery is a huge 45% and it was achieved by increasing the volume by just 5%.
We’ve been hoping that manufacturers will start focusing some effort on battery development and it’s great to see that LG finally did. The new SIO+ batteries should permit a notable extension of the battery life of smartphones and tablets without adding extra bulk.
The LG Optimus 4X HD features 4 powerful Cortex-A9 cores running at up to 1.5GHz but also a low-power fifth core. This core runs at about 500MHz and is used only for background tasks. So when the phone isn't under strain, it will drain the battery as slowly as a phone with a single 500MHz core.
We ran a quick benchmark and the 4X HD outpaces most of the old dual-core phones. The Tegra chipset also packs a 12-core NVIDIA GPU, which benchmarks well even with a high-resolution 720p display.
There's a developer option that shows which cores are active. After even a short time with the Optimus 4X HD, it became pretty clear that the low-power core is active for decent stretches of time and it's very hard to push the 4X into firing all four Cortex-A9 cores. The companion core even kicks in, when the 4X HD was playing 720p video, so we don’t think there’s any reason to doubt the Tegra 3 chipset power efficiency. Coupled with the huge battery, this one should do quite well in everyday usage.
We created a quick video to give you an idea of how quick the Optimux 4X HD actually is in real life.