Holy smoked motherboards Batman! Galaxy S4 hacker DSWR of the Android Central forums managed to overclock all 8 cores of his Model GT-I9500 to a screaming 2.8 GHZ. The results were, as you can imagine, rather devastatingly heated(I hope to see pictures of the destruction soon!)
He managed to trick the phone into believing it was in both power saving and performance modes simultaneously. This forced the powerful A15 quadcore to work simultaneously along with the less powerful A7 core. A configuration that is most definitely not supported with a stock kernel.
Believe it or not the phone was actually able to run for a while with this setup. For a glorious half an hour no Touchwiz lag was experienced. Sadly the phone was "completely knackered" after his session. The A7 chip completely burnt out, hopefully he'll find some use for the hardware.
So why would anybody want to do this? Anybody who knew enough to program a kernel that could enable such extreme overclocking would have to know what happens when you do something like that to a phone. The reasoning largely boils down to just wanting to see what the hardware is capable of. Anybody who owns one of the octa-core Galaxy S4 models can now brag that their phones are capable of a higher clock rate than their friends laptops. Of course, the hacker will gain all kinds of bragging rights.
So does anything useful come out of the shiny, smoking remains of the once proud Samsung Flagship? Well since DSWR was able to achieve a stable overclock (however temporary) at this insane speed, it stands to reason that a similarly configured S4 with a slightly lower clock speed might be able to run very quickly in a daily driver kernel. There still would be all kinds of negatives to an overclock like that. Lower battery life and shorter processor lifespan would be a couple.
For some speed freaks the tradeoffs may just be worth it. In addition OEMs like Samsung always look around in the hacker community for ideas. Even Google has borrowed a few features from ROMs like Cyanogenmod from time to time. The vibrant hacking community that surrounds all things Android is one of the platforms biggest assets. So thank you to all the hackers like DSWR who help make our experience better. For those who would like a technical explanation of how the 2.8 GHz speed was achieved I recommend you check out his post here. Then afterwards go check out our Google Plus and Facebook to stay up to date on all the latest Android news.