What is the difference between 32 bit and 64 bit in PC?

Differences between a 32-bit and 64-bit CPU

A big difference between 32-bit processors and 64-bit processors is the number of calculations per second they can perform, which affects the speed at which they can complete tasks. 64-bit processors can come in dual core, quad core, six core, and eight core versions for home computing. Multiple cores allow for an increased number of calculations per second that can be performed, which can increase the processing power and help make a computer run faster. Software programs that require many calculations to function smoothly can operate faster and more

Differences between a 32-bit and 64-bit CPU

A big difference between 32-bit processors and 64-bit processors is the number of calculations per second they can perform, which affects the speed at which they can complete tasks. 64-bit processors can come in dual core, quad core, six core, and eight core versions for home computing. Multiple cores allow for an increased number of calculations per second that can be performed, which can increase the processing power and help make a computer run faster. Software programs that require many calculations to function smoothly can operate faster and more efficiently on the multi-core 64-bit processors, for the most part.

Another big difference between 32-bit processors and 64-bit processors is the maximum amount of memory (RAM) that is supported. 32-bit computers support a maximum of 3-4GB of memory, whereas a 64-bit computer can support memory amounts over 4 GB. This feature is important for software programs used in graphic design, engineering, and video editing as these programs have to perform many calculations to render their images.

One thing to note is that 3D graphic programs and games do not benefit much, if at all, from switching to a 64-bit computer, unless the program is a 64-bit program. A 32-bit processor is adequate for any program written for a 32-bit processor. In the case of computer games, you'll get a lot more performance by upgrading the video card instead of getting a 64-bit processor.

In the end, 64-bit processors are becoming more and more commonplace in home computers. Most manufacturers build computers with 64-bit processors due to cheaper prices and because more users are now using 64-bit operating systems and programs. Computer parts retailers are offering fewer and fewer 32-bit processors and soon may not offer any at all.

the number of bits is an expression of how wide the word is in the pcu. what is a word? a word is a collection of individual switches that can be either on or off. how we interpret these collections is how we cause calculations and logic to be used in the heart of the machine. the smaller the word the simpler the “things that can be said to the machine” are. when we had 4 bit machines the words had to be collected together to make meaningful commands. 1+1 would have to be fed to the processor as ADD then no.1 then the second 1 then the EQUALS would be a call to get the result back. That took a

the number of bits is an expression of how wide the word is in the pcu. what is a word? a word is a collection of individual switches that can be either on or off. how we interpret these collections is how we cause calculations and logic to be used in the heart of the machine. the smaller the word the simpler the “things that can be said to the machine” are. when we had 4 bit machines the words had to be collected together to make meaningful commands. 1+1 would have to be fed to the processor as ADD then no.1 then the second 1 then the EQUALS would be a call to get the result back. That took a number of clock cycles to achieve. Now we can pass the whole equation as an operator and its operands asking for the result in one cycle. The operations can be much larger given the larger number of bits available to carry the information/commands. The other part of the bitness is the width of the data bus, that is the number of bits passed in parallel to the cpu and is the mechanism by which we address the memory of our machines. 4 lines of address bus can address 16 memory locations, 8 bits can address 256, thats (2^8)+1 so 64 bits is (2^64)+1 and thats significantly more than (2^32)+1. there are limits to finite devices and the data bus and word size has a tremendous affect of the abilities of a device to work quickly over a large amount of data. If you want more out of your machinery you need to put more into it. why are you still asking about 64bit ather than asking when the 128 or 256bit machines are coming.Because they are!

There is no “problem” … so there is no “why”. The question is moot. So I’m answering a modified question “Is there a problem …”, because prefixing a “Why” onto it assumes there already is.

Whoever told you that 32bit “stuff” cannot run or has issues when running on a 64bit doesn’t know what they’re talking about. The other way round is most definitely a problem.

It might be (note very slight “might”) that 32bit programs run just a tad slower than 64bit programs on some very rare 64bit systems - all else being equal. But even then the difference would be so slight that you’d be hard pressed to ev

There is no “problem” … so there is no “why”. The question is moot. So I’m answering a modified question “Is there a problem …”, because prefixing a “Why” onto it assumes there already is.

Whoever told you that 32bit “stuff” cannot run or has issues when running on a 64bit doesn’t know what they’re talking about. The other way round is most definitely a problem.

It might be (note very slight “might”) that 32bit programs run just a tad slower than 64bit programs on some very rare 64bit systems - all else being equal. But even then the difference would be so slight that you’d be hard pressed to even notice it. The reason this may happen is because most 32bit programs expect a certain size for things like integers - lo and behold, they’re 32bits in length. On a 64bit machine the default length of such is 64bits. So it may be that the processor is optimized to work with 64bit lengths and converting back-n-forth when running a 32bit process. Though most 64bit processors (read “nearly all”) would actually include a portion which operates on 32bit long values in any case - meaning no slowdowns at all.

The only thing which could concern you is the limits of resources imposed by 32bit. Especially stuff like RAM. 32bit can usually not use anything more than 2GB of RAM, with some settings extendible to just under 4GB. Or if possible using PAE an entire 32bit operating system can use 36bit RAM addressing, allowing for a maximum of 64GB RAM - though each program running on it would still have its own 32bit address space and can thus only use up to 2 or 4 GB of RAM for itself. This may mean a 32bit program cannot work on the same size of data a similar 64bit would be able to - but it would have had the same issue if the 32bit program was running on a 32bit machine - in which case the 32bit itself is the “problem”, not the fact that you’re running it on top of a 64bit machine.

You might be wasting resources by running a 32bit program on a 64bit machine. you’d most likely be wasting resources if you installed a 32bit operating system onto a 64bit machine (unless that machine didn’t have enough resources to begin with). If you consider the wastage a “problem” then this is as close to it as you can possibly come.

The terms 32-bit and 64-bit refer to the way a computer's processor (also called a CPU), handles information. The 64-bit version of Windows handles large amounts of random access memory (RAM) more effectively than a 32-bit system.

To install a 64-bit version of Windows, you need a CPU that's capable of running a 64-bit version of Windows. The benefits of using a 64-bit operating system are most apparent when you have a large amount of random access memory (RAM) installed on your computer, typically 4 GB of RAM or more. In such cases, because a 64-bit operating system can handle large amounts of

The terms 32-bit and 64-bit refer to the way a computer's processor (also called a CPU), handles information. The 64-bit version of Windows handles large amounts of random access memory (RAM) more effectively than a 32-bit system.

To install a 64-bit version of Windows, you need a CPU that's capable of running a 64-bit version of Windows. The benefits of using a 64-bit operating system are most apparent when you have a large amount of random access memory (RAM) installed on your computer, typically 4 GB of RAM or more. In such cases, because a 64-bit operating system can handle large amounts of memory more efficiently than a 32-bit operating system, a 64-bit system can be more responsive when running several programs at the same time and switching between them frequently.

You're probably aware that 64-bit and 32-bit versions of your operating system exist, but apart from ascribing to a bigger-is-better philosophy, you may have no idea what separates the two. The question: Should you use a 64-bit version of Windows, and why?

More and more frequently, users are installing the 64-bit version of their operating system of choice over the less capable 32-bit version. But most people don't really have a full understanding of what the difference really is. Below, we're taking a look at the most important differences so you can better understand what you gain (and potentially lose) if you upgrade to the 64-bit version of your OS. (The post focuses on Windows.)

We've already explained whether you really need 4 GB of RAM, a question that touches on the 64-bit issue, but now let's tackle it in more detail.

With the price of upgrading system RAM extremely low these days, people are always asking me….

Which Version Do I Have?

To figure out which version of Windows you are running, just head into the System properties in Control Panel, or you can take the easy route and right-click on your Computer icon in the start menu or desktop, and choose Properties from the menu. Windows 7 or Vista users will be able to check the System type in the list, while the few XP users with 64-bit will see it on the dialog.

Keep in mind that your CPU must support 64-bit in order to be running a 64-bit operating system—if you're running a modern CPU you should be fine, but some of the budget PCs don't include a 64-bit processor.

Does 32-bit Really Have a Memory Limit?

In any 32-bit operating system, you arelimited to 4096 MB of RAM simply because the size of a 32-bit value will not allow any more. On a 32-bit system, each process is given 4 GB of virtual memory to play with, which is separated into 2 GB of user space that the application can actually use at a time.

Savvy readers might point out that modern chips support PAE, a processor technology that allows the operating system to use a little bit more memory—up to 64 GB, but it also requires special application support that most applications don't have or necessarily need.

A common misconception is that this is a Windows-specific problem, when in fact 32-bit Linux and Mac OS X have the same limitations and the same workarounds. 32-bit Linux uses a mapping table to allow access to the extra memory, and OS X Snow Leopard actually ships by default with a 32-bit kernel that can't access all the memory on older systems, even though most of the rest of the OS runs 64-bit processes.

The 4 GB limit for Windows, at least, is also a factor of licensing—the home versions of 32-bit Windows, while technically being able to support PAE, have a hard limit of 4 GB for licensing and driver compatibility reasons.

More Problems with 32-Bit

Not only does 32-bit have a hard limit for the amount of memory it can address, there's also another problem: your devices, like your video card and motherboard BIOS take up room in that same 4 GB space, which means the underlying operating system gets access to even less of your RAM.

Windows expert Mark Russinovich found that a desktop running 32-bit Windows with 4 GB of RAM and two 1 GB video cards only had 2.2 GB of RAM available for the operating system—so the bigger and better your video cards get, the less of that 4 GB will be accessible on a 32-bit system.

What's Different About 64-Bit?

While 32 bits of information can only access 4 GB of RAM, a 64-bit machinecan access 17.2 BILLION gigabytes of system memory, banishing any limits far into the future. This also means that your video cards and other devices will not be stealing usable memory space from the operating system. Windows 64-bit Home editions are still limited to 16 GB of RAM for licensing reasons, but the Professional and Ultimate versions can use up to 192 GB of RAM, so keep that in mind when building that killer system.

The per-process limit is also greatly increased—on 64-bit Windows, instead of a 2 GB limit, each application has access to 8 TB of virtual memory without any special API, a huge factor when you consider applications like video editing or virtual machines that may need to use enormous amounts of RAM.

On Windows, the 64-bit versions also come with a technology to prevent hijacking the kernel, support for hardware-enabled data execution protection, and mandatory digitally signed 64-bit device drivers. You also won't be able to use your 16-bit apps anymore, which hardly seems like a loss.

Do 32-bit Applications Work on 64-Bit?

The vast majority of your 32-bit applications will continue to work just fine on 64-bit Windows, which includes a compatibility layer called WoW64, which actually switches the processor back and forth between 32-bit and 64-bit modes depending on which thread needs to execute—making 32-bit software run smoothly even in the 64-bit environment.

There are some exceptions to that rule, however: 32-bit device drivers and low-level system applications like Antivirus, shell extensions that plug into Windows, and some media applications simply won't work without a 64-bit equivalent.

In practice, the vast majority of your favorite applications will either continue to work, or provide a 64-bit version you can use instead—but you should check to make sure.

Does 64-Bit Use Double the RAM?

A common misconception about 64-bit Windows is the amount of RAM that is actually used—some people seem to think it will use double the RAM, while others incorrectly assume a 64-bit system will be twice as fast as 32-bit.

While it's true that 64-bit processes will take a little extra memory, that is a result of the memory pointers being a little bigger to address the larger amount of RAM, and not an actual double in size. Imagine, if you will, an ancient library filing system that has a card to tell you where to find the book in the library—if you got a bigger box to hold the cards, the library would not double in size, you'd just be able to find the book you were looking for more easily.

What will increase with 64-bit Windows is the amount of drive space needed for the operating system—with a compatibility layer in place, the base OS will take up a few extra GBs of space, though with today's massive hard drives that should hardly be a concern.

The Bottom Line, Which Should I Use?

If you are ordering a new PC with 4 GB or more of RAM, you should probably be running a 64-bit version of Windows so you can use all of the available memory, especially if you want a rig with a large video card—just keep in mind that the Home versions only support 16 GB of RAM (for most people a 16GB limit won't be a problem, but it's worth keeping in mind).

If you're running Mac OS X, you don't need to worry about 32-bit vs 64-bit, and if you're running Linux, you probably know this stuff already.

Hope you got the Answer let me know if not…..

What are bits?

The number of bits in a processor refers to the size of the data types that it handles and the size of its registry. A 64-bit processor is capable of storing 264 computational values, including memory addresses, which means it’s able to access over four billion times as much physical memory than a 32-bit processor!

The key difference: 32-bit processors are perfectly capable of handling a limited amount of RAM, and 64-bit processors are capable of utilizing much more. Of course, in order to achieve this, your operating system also needs to be designed to take advantage of the great

What are bits?

The number of bits in a processor refers to the size of the data types that it handles and the size of its registry. A 64-bit processor is capable of storing 264 computational values, including memory addresses, which means it’s able to access over four billion times as much physical memory than a 32-bit processor!

The key difference: 32-bit processors are perfectly capable of handling a limited amount of RAM, and 64-bit processors are capable of utilizing much more. Of course, in order to achieve this, your operating system also needs to be designed to take advantage of the greater access to memory

How many bits?

As a general rule, if you have under 4 GB of RAM in your computer, you don’t need a 64-bit CPU, but if you have 4 GB or more, you do. While many users may find that a 32-bit processor provides them with enough performance and memory access, applications that tend to use large amounts of memory may show vast improvements with the upgraded processor. Image and video editing software, 3D rendering utilities, and video games will make better use of a 64-bit architecture and operating system, especially if the machine has 8 or even 16 GB of RAM that can be divided among the applications that need it.

Through hardware emulation, it’s possible to run 32-bit software and operating systems on a machine with a 64-bit processor. The opposite isn’t true however, in that 32-bit processors cannot run software designed with 64-bit architecture in mind. This means if you want to take full advantage of your new processor you also need a new operating system, otherwise you won’t experience any marked benefits over the 32-bit version of your hardware.

Operating System Differences

With an increase in the availability of 64-bit processors and larger capacities of RAM, Microsoft and Apple both have begun to develop and release upgraded versions of their operating systems that are designed to take full advantage of the new technology.

In the case of Microsoft Windows, the basic versions of the operating systems put software limitations on the amount of RAM that can be used by applications, but even in the ultimate and professional version of the operating system, 4 GB is the maximum usable memory the 32-bit version can handle. While a 64-bit operating system can increase the capabilities of a processor drastically, the real jump in power comes from software designed with this architecture in mind.

Software and Drivers

Applications with high performance demands already take advantage of the increase in available memory, with companies releasing 64-bit versions of their programs. This is especially useful on programs that can store a lot of information for immediate access, like image editing and software that opens multiple large files at the same time.

Video games are also uniquely equipped to take advantage of 64-bit processing and the increased memory that comes with it. Being able to handle more computations at once means more spaceships on screen without lagging and smoother performance from your graphics card, which doesn’t have to share memory with other processes anymore.

Most software is backwards compatible, allowing you to run applications that are 32-bit in a 64-bit environment without any extra work or issues. Virus protection software and drivers tend to be the exception to this rule, with hardware mostly requiring the proper version be installed in order to function correctly.

How did you determine your computer is 32-bit?
There are two points here.
You can have a 32-bit OS on a 64-bit processor.
Or your processor itself maybe 32-bit.
The first case is easy to solve. Just install a 64-bit OS. Windows, Linux and OSX all now have 64-bit versions.

If your processor itself is only 32-bit, then you have no option but to change it.
How old is your computer? If it is from the last 6 to 7 years (2008 - Present), you most probably will have 64-bit processor. If it is between 8 and 2 years old (2003 - 2008) there is a good chance it might not be 64-bit. If it older than that,

How did you determine your computer is 32-bit?
There are two points here.
You can have a 32-bit OS on a 64-bit processor.
Or your processor itself maybe 32-bit.
The first case is easy to solve. Just install a 64-bit OS. Windows, Linux and OSX all now have 64-bit versions.

If your processor itself is only 32-bit, then you have no option but to change it.
How old is your computer? If it is from the last 6 to 7 years (2008 - Present), you most probably will have 64-bit processor. If it is between 8 and 2 years old (2003 - 2008) there is a good chance it might not be 64-bit. If it older than that, then it certainly cannot be 64-bit.
If you have a laptop, you will need to buy an entirely new one.
If you have a desktop, you can change the Processor. But changing the processor will almost certainly mean changing the motherboard. And changing the motherboard will mean changing the RAM and other components. If you know what you are doing, you can keep some components and change only those that are incompatible with the motherboard.

Source:
https://en.wikipedia.org/wiki/64-bit_computing#64-bit_processor_timeline
(AMD's 64bit processors came out in 2003 and Intel's processors came out in 2006)

Differences between a 32-bit and 64-bit CPU

A big difference between 32-bit processors and 64-bit processors is the number of calculations per second they can perform, which affects the speed at which they can complete tasks. 64-bit processors can come in dual core, quad core, six core, and eight core versions for home computing. Multiple cores allow for an increased number of calculations per second that can be performed, which can increase the processing power and help make a computer run faster. Software programs that require many calculations to function smoothly can operate faster and more

Differences between a 32-bit and 64-bit CPU

A big difference between 32-bit processors and 64-bit processors is the number of calculations per second they can perform, which affects the speed at which they can complete tasks. 64-bit processors can come in dual core, quad core, six core, and eight core versions for home computing. Multiple cores allow for an increased number of calculations per second that can be performed, which can increase the processing power and help make a computer run faster. Software programs that require many calculations to function smoothly can operate faster and more efficiently on the multi-core 64-bit processors, for the most part.

Another big difference between 32-bit processors and 64-bit processors is the maximum amount of memory (RAM) that is supported. 32-bit computers support a maximum of 3-4GB of memory, whereas a 64-bit computer can support memory amounts over 4 GB. This feature is important for software programs used in graphic design, engineering, and video editing as these programs have to perform many calculations to render their images.

One thing to note is that 3D graphic programs and games do not benefit much, if at all, from switching to a 64-bit computer, unless the program is a 64-bit program. A 32-bit processor is adequate for any program written for a 32-bit processor. In the case of computer games, you'll get a lot more performance by upgrading the video card instead of getting a 64-bit processor.

In the end, 64-bit processors are becoming more and more commonplace in home computers. Most manufacturers build computers with 64-bit processors due to cheaper prices and because more users are now using 64-bit operating systems and programs. Computer parts retailers are offering fewer and fewer 32-bit processors and soon may not offer any at all..

I have already answered this on another thread but saw the same thread so answered again.

In layman’s terms:

A computer is nothing more than a collection of switches.

A switch can only be either on (1) or off (0), hence the base number system computers use being binary (1 or 0).

In decimal where every placeholder increases the amount of numbers available by a power of 10 (units, tens, hundreds, thousands, ten thousands, etc.), binary numbers increase by a power of 2 for every placeholder (1, 2, 4, 8, 16, 32, 64, 128, etc.)

So a 32 bit (placeholder) CPU can address up to 4,294,967,296 bits (2 to the 32) or 4.3 Billion. Sounds like a lot but it has massive limitations in terms of address

In layman’s terms:

A computer is nothing more than a collection of switches.

A switch can only be either on (1) or off (0), hence the base number system computers use being binary (1 or 0).

In decimal where every placeholder increases the amount of numbers available by a power of 10 (units, tens, hundreds, thousands, ten thousands, etc.), binary numbers increase by a power of 2 for every placeholder (1, 2, 4, 8, 16, 32, 64, 128, etc.)

So a 32 bit (placeholder) CPU can address up to 4,294,967,296 bits (2 to the 32) or 4.3 Billion. Sounds like a lot but it has massive limitations in terms of addressable memory space (4 Gigabytes of RAM - 4.3 Billion addresses).

Now a 64 bit CPU can theoretically address up to 2 to the 64 or 18,446,744,073,709,551,646 bits - a whole lot more.

I say theoretically because other factors come into play and that much memory would create bottlenecks of other sorts.

So the answer is a 64 bit CPU can address more memory than a 32 bit CPU.

(disclaimer - this is a massively simplified version of the truth and is full of errors and omissions, hey you asked for the layman’s version!)

Copying from my answer Rajesh Nair's answer to Can Java code compiled using 64-bit jdk run on 32-bit jre?

The difference in 32-bit and 64-bit can occur at 3 different layers

  1. Processor : A 32 bit processor is one which handles instruction set using 32 bit addressing and hence can point to physical memory upto 4GB. A 64 bit processor uses 64-bit addressing and can point physical memory > 4GB. Hence in order to *effectively* use RAM more than 4GB , you should have processors of 64-bit.
  2. OS : An OS can be 32-bit or 64-bit which effectively means the virtual memory they support. A 64-bit operating sy

Copying from my answer Rajesh Nair's answer to Can Java code compiled using 64-bit jdk run on 32-bit jre?

The difference in 32-bit and 64-bit can occur at 3 different layers

  1. Processor : A 32 bit processor is one which handles instruction set using 32 bit addressing and hence can point to physical memory upto 4GB. A 64 bit processor uses 64-bit addressing and can point physical memory > 4GB. Hence in order to *effectively* use RAM more than 4GB , you should have processors of 64-bit.
  2. OS : An OS can be 32-bit or 64-bit which effectively means the virtual memory they support. A 64-bit operating systems which has ability to create virtual memory larger than 4 GB. Theoretically , they can run on top of 32 bit processors as well but they will not be much useful. In fact, when Linux became the first OS to fully support x86_64 in 2001, it was developed on simulators on 32-bit processors.
  3. Native Application : These are applications which are compiled to 64-bit addressing system to fully utilize 64 bit OS. A 64 bit JRE is a native application compiled using 64-bit compilers for that specific OS/processor combination ( aka platform).

Hope this answers!

Generally 32-bit as many others have said, because the 64-bit code usually takes more RAM, and swapping sucks.

If what you are doing fits in the 2GB without swapping, it is likely that 64-bit versions of your apps will run faster even in 2GB, because x86–64 has operations working on larger pieces of data at a time than 32-bit x86 and has twice as many registers to work with, and other advantages, for example, 32-bit code might not use SSE2 by default because it would have to check if the processor supported it and provide a non-SSE codepath to fall back on. But every x86–64 processor supports i

Generally 32-bit as many others have said, because the 64-bit code usually takes more RAM, and swapping sucks.

If what you are doing fits in the 2GB without swapping, it is likely that 64-bit versions of your apps will run faster even in 2GB, because x86–64 has operations working on larger pieces of data at a time than 32-bit x86 and has twice as many registers to work with, and other advantages, for example, 32-bit code might not use SSE2 by default because it would have to check if the processor supported it and provide a non-SSE codepath to fall back on. But every x86–64 processor supports it, so 64-bit code would never have those optimizations off.

But if you are swapping, at all, that will outweight everything else.

To the very basic,

If it is 32 bit operating system it means 32 bits can be processed at a time(or in a moment)

If it is 64 bit operating system it means 64 bits can be processed at a time(or in a moment)

If your processor is a 64 bit processor you can install a 64 bit operating system, if your processor is a 32 bit processor you can replace it with a processor of 64 bit and then install a 64 bit operating system.

Process interoperability issues would be encountered in this scenario:

On 64-bit Windows, a 64-bit process cannot load a 32-bit dynamic-link library (DLL). Additionally, a 32-bit process cannot load a 64-bit DLL. However, 64-bit Windows supports remote procedure calls (RPC) between 64-bit and 32-bit processes (both on the same computer and across computers).

Reference: Process Interoperability - Win32 apps

To differentiate between the two you will need to check the PE header:

See this MSDN article on the PE File Format for an overview. You need to read the MS-DOS header, then read the IMAGE_NT_HEA

Process interoperability issues would be encountered in this scenario:

On 64-bit Windows, a 64-bit process cannot load a 32-bit dynamic-link library (DLL). Additionally, a 32-bit process cannot load a 64-bit DLL. However, 64-bit Windows supports remote procedure calls (RPC) between 64-bit and 32-bit processes (both on the same computer and across computers).

Reference: Process Interoperability - Win32 apps

To differentiate between the two you will need to check the PE header:

See this MSDN article on the PE File Format for an overview. You need to read the MS-DOS header, then read the IMAGE_NT_HEADERS structure. This contains the IMAGE_FILE_HEADER structure which contains the info you need in the Machine member which contains one of the following values

  • IMAGE_FILE_MACHINE_I386 (0x014c)
  • IMAGE_FILE_MACHINE_IA64 (0x0200)
  • IMAGE_FILE_MACHINE_AMD64 (0x8664)

This information should be at a fixed offset in the file, but I'd still recommend traversing the file and checking the signature of the MS-DOS header and the IMAGE_NT_HEADERS to be sure you cope with any future changes.

Reference: How can I test a Windows DLL file to determine if it is 32 bit or 64 bit?