Samsung Galaxy S II, popularly known as SGS2, is being overclocked to 1.504 GHz successfully by coolbho3000, a senior member of xda. This speed of this mobile phone is good as far as allowing it to achieve high benchmark scores like 4000 points in Quadrant. 1.5 Ghz is 25% overclock and this hack makes it more fast.

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OverClocking Samsung Galaxy S II SGS2

1. Your SGS2 must be rooted for this. Follow this [Tutorial for Rooting]

2. Download Odin 1.83 from here [Links]

3. You need the drivers installed for your device. Samsung Kies will help you to do so. [Links]

4. Download Overclocked kernel for SGS2 [Links]

5. using ADB, reboot your device into the download mode
adb reboot download

6. Start ODIN.

7. Connect the device to pc.

8. Using Odin3, in PDA section place the tar file that you downloaded in Step4 and press ‘Start’ and flash the kernel.

9. Your phone will reboot now.

10. From Android Market, download SetCPU

11. Install it on your phone.

12. Set the speed to 1.5GHz.

13. Reboot your smartphone.

The hacker says that 1.504 Ghz is stable at 1375mV on his phone. He has got speeds of upto 2Ghz. But if you stress your CPU more, it will become very hot, though even at stock frequencies, it does to some extent and there is not so much thermal insulation between your hands and the processor in such a slim device.

The kernel has 1.504 Ghz overclocking but for safety, default frequency is still 1.2GHz and you can use SetCPU to safely raise frequency level.

All support at xda thread