64 bit vs 32 bit [closed]

Question

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32-bit vs. 64-bit systems

When I was doing my course MCSA, I'm taught the following:

1. With a 32-bit processor only 32-bit operating system can be installed.
2. with a 64-bit processor both 32-bit & 64-bit operating system can be installed

It's said 64-bit os cannot be installed on a 32-bit processor.

I just want to make sure the above points because recently I'm asked to installed Windows Server 2008 R2 Enterprize and while installation it showed only x64 and it simply installed it. I was thinking all the computers in my office having a 32-bit processor. If so how it could be possible to install a x64 bit os on a 32-bit processor? or I'm wrong with the 1st point or the processor may be of 64-bit(I don't know how to check). I'm confused...

One thing what I know the benefits of 64-bit over 32-bit is faster operation. If anyone could tell me other benefits, it could be helpful for me.

EDIT 1: Two more questions:

1. Is there any drawbacks installing 32-bit os on a 64-bit processor?
2. Any drawback if I install 32-bit applications on a 64-bit os

Thanks!

Answer 1

On the two points you made, you are correct. 32bit CPUs only support 32bit OSs. 64bit CPUs can support both 32bit and 64bit OSs.

64bit hardware (when running 64bit OS and software) support more RAM and more CPUs than 32bit software can which is very important when running very large database servers, exchange servers, etc.

Once you have Windows installed one of the easiest way to see if you have a 64bit OS installed is to look at the processes tab in Task Manager. If you see a bunch of processes with *32 after the "Image Name" then you have 64bit processes as these ones with the *32 are 32bit processes running under a 64bit OS. You can also look for the "C:\Program Files (x86)\" folder. You can also right click on "My Computer" and select properties. There's a field under "System" called "System type" which will tell you if it is 64 or 32 bit. The computer BIOS will tell you, but every system BIOS is different so you'll have to hunt and peck to find it.

If the computer was purchased within the last couple of years odds are it is a 64bit CPU. While you can still buy 32bit systems they are becoming harder and harder to find and some software doesn't support the 32bit platform any more (such as Microsoft Exchange 2010).

Answer 2

I will assume you are talking about Intel or AMD processors. The answer is they support multiple modes of operation. http://en.wikipedia.org/wiki/Long_mode

Answer 3

To add onto the good answers you have already received, if a box has windows on it already, you can download cpu-z to check the processor capabilities to see if 64-bit support is there.

To support a 64 bit Operating System, you need a 64 bit processor plus 64 bit drivers for all the components you wish to use on that system. This isn't a problem for most systems released in the last few years, but I think there were issues with earlier hardware that was 64-bit capable but had very ropey driver support.

As Mr Denny says in his answer, most system that have been released in the last few years should offer 64-bit support, the one immediate exception I can think of is the core duo (not the core2duo) and the Atom.

As for speed - a 64-bit system (processor + OS) will not be faster than an otherwise equal 32-bit system for most operations; the benefits of 64-bit systems lie at the higher end of things such as better support for large memory.

Answer 4

One significant advantage is simply that the processor has a 64bit ALU instead of a 32bit and can therefore calculate big integers faster. ;) This is helpful especially with image processing, cad, encryption, gaming and so on..
But this is also its greatest disadvantage as 64bit values always use 64bit even if they are smaller. So when you have a program that uses mostly small values instead of big ones it will take longer to compute them than on a 32bit machine.
But practically I guess you won't really notice it.
My biggest problem with 64bit was driver-related. But it was Linux though..

Greetings from Berlin!

Answer 5

I was thinking all the computers in my office having a 32-bit processor.

You can see what processor is installed checking the BIOS of the machine, computer startup screens and the properties of the computer in the installed Windows.

Unless your office runs VERY old computers, there is no such thing anymore as a 32 bit processor. For quite some years pretty much all desktop and server processors are 64 bit.

One thing what I know the benefits of 64-bit over 32-bit is faster operation.

This isn't correct: 64 bit and 32 bit are same speed. Actually 32 bit programs are a little faster (smaller pointers, i.e. faster processing). 64 bit comes in handy when a program needs more address space than a 32 bit process provides (3gb on a 64 bit windows, 2gb / 3gb depending on circumstancs on 32 bit).

Then the slightly slower nature turns out big advantage in address management. A LOT of software simply does not need it - like MS Word, for example... hard to imagine what a 32gb Word document would look like.

The one and pretty much only advantage of 64 bit is larger address space. Point. Handy to run multiple programs side by side, or for certain programs that really like a lot of memory (database servers, for example).