differnce between 32 bit OS and 64 bit OS

[harshagarwal]

i want to know what is the difference between 32 bit OS and 64 bit OS?

coz i thought its the hardware but read some post here that MS is launhing 64 bit OS.

got confused please help.

 

[swatkat]

32 bit and 64 bit refers to memory (RAM) addressing capability.
Current processors are 32 bit, this means they can generate numbers of length 32 bits to address memory cells in RAM. This offers a limit of 4GB or RAM.
So, current OS and Softwares use 32bit addressing scheme to address RAM in their codes. When these codes are executed in ALU of Processor, the 32 bit address is passed to Memory Controller, which then locates the corresponding location in RAM.

64 bit processors support 64 bit addressing scheme. That is they can generate addresses of 64 bit lenght, so they can address upto 16 Exabytes of RAM (1 Exabyte=billion billion bytes).
Current Softwares and OS are not written with the 64 bit addressing scheme, but they are written for 32 bit addressing scheme, so they can make use of only 4GB out of 16 Exabytes or RAM (if you put that much of RAM, that is!).
So, these softwares should be rewritten to adopt 64 bit addressing scheme, in order to exploit the full potential of 64 bit processor.

Current processors use 32 bit Instruction length, but in 64 bit processors, instruction length may also be larger, this results in a new set of instructions. These new instructions are not made use of, by current softwares.

 

[drgrudge]

Remember 64 bit softwares (inc. OS ; win xp 64-bit) wont run on your current 32-bit hardware. U need to a get a 64 -bit precessor as well.
Even we linux has 64- bit OS (fedora core and unbuntu).

But remember , we can run 32-bit applications as well. But there will be issues. (my system even dont dont run 16-bit applications).
1. Apps that install or require 32-bit kernel-mode drivers wont work in this 64-bit thing.
2. U can't run 16-bit application as well. windows installer is one of them.

And remember u use 32-bit apps the most at present and there are not enough 64-bit apps as such.

What will u do with a 64-bit processor (AMD athlon FX) ?
then it was released.
What will u do with a 64-bit processor and 64-bit OS?
Hmmm...the point is when u dont have proper application to run on these... but i may tell even 32-bit is not properly utilised.

Hmm... lets see what windows XP 64-bit walla will have in it..., i mean the other apps, leave the OS.

Even when u have a 64-bit walla processor , u will be using a 32-bit walla OS and apps. Whats the use of it now? U wont find any difference in the performance.

 

[harshagarwal]

hey thanx for the info man it was quiet informative