Difference Between Cold Booting and Warm Booting (with Comparison Chart)

Cold booting VS Warm booting In a broad sense, Booting is a process of starting a computer and specifically handing over the control to the operating system. There are two forms of booting, Cold Booting and Warm Booting, here we are going to learn the difference between them. The notable difference between them is that the Cold Boot occurs at the beginning where the state of the primary components of the computer and RAM is checked with the help of Power On Self Test (POST) before loading the operating system. Conversely, Warm Boot skips the primary self-test and starts loading the operating system directly.

The procedure followed in the past days of computing was completely different where the programs were manually inserted in a computer before using them. However, today, this not the scenario, the applications and programs are once installed can be used any time.

Now, let’s understand what is booting process thoroughly. Booting can be defined as a process of starting a computer by loading the fundamental elements of the operating system into its main memory. In the booting process, the operating system is first searched, loaded, and at last, all the control of the system is given to the operating system. This is done with the help of the ROM (Read Only Memory) chip where the booting commands are embedded and triggered when a user turns ON a computer or performs RESET on a computer.

Content: Cold Booting Vs Warm Booting

Comparison Chart

Basis for comparison	Cold Booting	Warm Booting
Basic	Turning a computer on from a powerless state.	Resetting a computer that is already in running state.
Initialized by	Power button	Reset button or by pressing Ctrl+Alt+Del simultaneously.
Performed	In a frequent basis.	Not very common.
Consequence	Does not affect the data or other hardware.	Can severely affect the system causing the data loss.
Alternate names	Hard Booting, Cold start and dead start.	Soft Booting
POST (Power On Self Test)	Is included	Not included

Definition of Cold Booting

At this point, we know what the booting process is, in a general way. Now, what is the cold booting? It is the first thing that a computer does when we turn it ON from OFF position. In the very first stage, the microprocessor is initialized. The steps conducted to perform a cold booting process are described below:

Cold Booting Steps

Once a computer is switched ON, it loads the IR (Instruction Register) automatically with the predefined memory location, and this makes the instructions ready to execute. The basic bootstrap program which is generally stored in the ROM is located at the memory location.
The main job of the bootstrap program is to execute a diagnostic test that examines the state of the different components of the computer system, and this is known as the Power On Self Test (POST). It involves the testing of the system bus, video display card, internal clock, RAM, disk drivers and keyboard. A short beep generated by speaker signifies that the test is successful.
After passing the POST check, it reads a block of code from the boot sector (i.e., a tiny section of the hard disk) and loads it into the main memory. This block of code keeps information concerning the location of the remaining portion of the bootstrap program, which is loaded next.
When the complete bootstrap program is loaded, the operating system kernel and device drivers are loaded into the memory to make the computer function properly.

Definition of Warm Booting

Warm Booting is different from the Cold Booting because it is not performed in the initial phase of starting the device (computer). It also skips the POST test. If your computer hangs due to some reason while working, and requires to be restarted to make it functional. The resetting or restarting of the computer is known as warm booting. It can be performed using the reset button or pressing the particular keys (i.e., Ctrl+Alt+Del) concomitantly. In this type of booting RAM is not tested as there is no Power On Self Test is performed.

Limitations

In certain cases, warm booting can be harmful to the system and the data due to the forced conducts over the files and the applications for closing them. In other words, triggering a boot when a file and application is open could result in losing the valuable data as one does not get any chance to save the data to the disk before the boot takes place. It can also cause some system issues where the system might halt completely.

Key Differences Between Cold Booting and Warm Booting

A cold booting is when you turn ON the computer from an OFF position. On the other hand, the warm booting is when you reset a computer that is already in its ON state.
To initialize the cold booting, we need to turn ON the power button. In contrast, warm booting is carried out by using the reset button and pressing the keys Ctrl, Alt and Del, twice at the same time.
We perform cold booting very oftenly, however warm boot is quite rarely carried out.
Cold is a safe type of booting, but warm booting can be fatal. The outcomes of the warm booting can be severe for the system, and the data, especially that has not been saved.
The cold booting conducts the POST test to check the various computer components. As against, during warm booting, the POST test is avoided.

Conclusion

We all are aware of these two processes as we perform cold and warm Booting on a daily basis if we are using electronic computing devices. The overall effect of either of the process is to close all the running processes and tasks of an operating system and ultimately closing or resetting the operating system.