[Galaxy S 4 General] bala_gamer:
Galaxy S4 9500 only​

Standard Disclaimer: Im not responsible if something wrong happens to your device ;) Read the guide as much as you want before proceeding with overclocking

Overclocking and undervolting is highly debatable, some say its good and some say its bad... so its upto you to decide and proceed further

First rule of overclocking.. Your Mileage May Vary​

Most of the people here in xda do know about overclocking and stuffs but still there are many who are so eager to overclock their device . Hence this guide.

I have given some good info below about these stuffs as far as i can , you can always use google to get further details.

What is overclocking?

Overclocking is the process of making a computer or component operate faster than the specified clock frequency by the manufacturer by modifying system parameters. One of the most important techniques is running at a higher clock rate (more clock cycles per second; hence the name "overclocking")

Operating voltages may also be changed (increased), which can increase the speed at which operation remains stable.

Advantage:

You can get more performance from your chipset, though s4 is already fast you can see the visible changes in application execution time and much more like instant response time.

Disadvantage:

* Overclocking is always risky if something is configured improperly and may also result in permanent damage to your hardware. As long as it is done safely you are good to go.

* You may see some increased power consumption.

* Extreme overclocking might kill your hardware.

Undervolting :

The process where you provide less voltage to your cpu rather than the stock voltage.

Advantage:

* Reduced heat from your device.

* Good battery life.

Disadvantage:

* Extreme undervolting will make your device unstable and some times even end up with a boot loop.

Apart from the voltage table defined below for exynos the below mentioned data are common for 9500/9505

Overclocking in Exynos Octa:

Exynos 5410 is already one among the best performing chipset available, so overclocking this device is not going to give us any visible performance improvements except the benchmark scores. Underclocking is a different story on 9500, since the cpu temperature easily reaches upto 90C (90C is the throttle temperature defined for this device in the kernel, so its normal) undervolting the device will help in reducing the overall temperature of the device considerably. I highly recommend undervolting the device instead of overclocking it.

Exynos 5410 has 2 cpu clusters, stock voltages and available steppings are given below

Little Cores (A7) stock voltages

[B]STWEAKS[/B]

1200mhz : 1225mv
1100mhz : 1125mv
1000mhz : 1100mv
900mhz : 1037mv
800mhz : 987mv
700mhz : 950mv
600mhz : 950mv
500mhz : 950mv
400mhz : 950mv
300mhz : 950mv
200mhz : 950mv

Samsung divides the actual clock of a7 by 2 while displaying the steppings in order to accommodate the big little way of displaying values. Stweaks will show you every available steppings like above whereas most other cpu tuning apps show it like below, both are same though. stweaks @ 800mhz is equal to other tuning apps @ 400mhz

[B]OTHER CPU TUNING APPS[/B]

700mhz : 1225mv
550mhz : 1162mv
500mhz : 1100mv
450mhz : 1037mv
400mhz : 987mv
350mhz : 950mv
300mhz : 950mv
250mhz : 950mv
200mhz : 950mv
150mhz : 950mv
100mhz : 950mv

Big Cores (A15) stock voltages

2000mhz : 1250mv
1900mhz : 1250mv
1800mhz : 1250mv
1700mhz : 1200mv
1600mhz : 1162mv
1500mhz : 1137mv
1400mhz : 1100mv
1300mhz : 1062mv
1200mhz : 1025mv
1100mhz : 1000mv
1000mhz : 962mv
900mhz : 925mv
800mhz : 900mv

Though the cpu frequency table has steppings upto 2ghz the max stable clock i have seen so for on s4 is 1800mhz.

Requirements:

1. Kernel with overclocking/undervolting support.

2. stweaks or android tuner to change frequency/voltage.(you can use the app of your choice here).

3. set cpu and stability test to test the stability of CPU.

4. Some patience.

The below mentioned steps are common for 9500/9505

Step 1:

Set the current clock and voltage you want to test via android tuner/stweaks. (Select max frequency in cpu tab).

Example:

*If you want to test under volting for 1.4 ghz with 1050 mv (1100 is the default) then set 1.4 ghz as max clock and 1050mv as its voltage.

*If you want to test overclocking @ 1.7 ghz with 1150 mv (1200 is the default) then set 1.7 ghz as max clock and 1150 mv as its voltage.

Step 2:

Open set cpu's cpu stress test and run it for atleast 10 minutes. If you didnt get any errors or hang during the testing period and if the test completed successfully then the clock is ready for daily use

Step 3:

Now for undervolting use the same tools and reduce the voltage by -25mv.

Repeat step 2.

you can reduce the voltage further by -25 mv after every successful completion of stress test (Advanced users can try reducing -50mv )

Step 4:

Repeat step 1,2 and 3 for every possible cpu clock you see in android tuner/stweaks.

Note the stable cpu voltage for every clock, once you finish testing all your clock values save it as a profile and/or set it on boot.

Voila !!! now you have finished overclocking/ under voting your device.

Notes:

1. Never ever use set on boot option until you find the stable clock and voltage settings.

2. Not all chips are capable of running at higher speeds like 1800 mhz. Those speeds are highly experimental.

3. Recommended max overclocking is 1700 mhz.

4. If your device gets hotter allow the device to cool for few minutes before starting the test.

5. Either use stweaks or android tuner(or some other app), dont mix up.

6. Combining the overclocking and undervolting will give you the best of both the worlds :)

In case of emergency:

1. If your device becomes unstable and not responsive either press the power button until your device restarts or pull out your battery.

2. Android tuner has an option to create flashable zip for resetting the voltage table, use it if needed.

*********************Do note me if any information is incomplete or wrong :p ill change it.*******************************

Credits :

* wikipedia

* [MENTION=4167023]AndreiLux[/MENTION] and [MENTION=3562083]wanam[/MENTION] for their outstanding work on kernel development