Yes, Plutonium Mode is an enhancement to Minecraft’s code to ensure the game takes advantage of multiple processor cores. With the Better Together Update streamlining Minecraft across systems and platforms, optimization seems to be central to Mojang’s plans for Minecraft, and Plutonium Mode is an experiment in 1.2 build 5.
Users on the Minecraft Forum and SubReddit report that using the mode with newer devices (i.e. anything that has 4 or more cores in the processor) gives them a significant jump in frames per second – usually 10 to 15 fps, depending on the system. Plutonium Mode is available on every version of Minecraft, but not all users will see a benefit from switching it on.
Players with newer PCs – the types that can run PUBG in 4K at 120 fps – probably won’t see a difference, since their system is powerful enough to brute force its way past most limitations. Players who use older phones and tablets also won’t see an increase in performance, because those devices only have 2 processor cores.
If you have an iPhone 7 or better, iPad Air 2, or an iPad Pro, you’ll see an increase in your fps. iPad Minis and anything older won’t benefit. Likewise for Kindle Fires from 2013 or earlier: they only have dual-core processors. If you’ve got an Android tablet or phone, check the specifications to see if your device has a quad-core processor. Most new devices will have chipsets capable of taking advantage of Plutonium Mode. Even my aging Galaxy S5 Active has a quad-core chipset!
u/mojang_tommo confirmed on Reddit that Plutonium Mode is a proof-of-concept addition for the newly-minted Better Together Update, and it will be standard in Minecraft update 1.3:
It looks like Minecraft is only going to get smoother, better, and more accessible in the future.
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