64bit vs 32bit

if you are A person who uses a lot of programs all at once on a computer then you will need more ram and if you want a lot of ram to uses those programs all at once without stuttering then you would need a 64 bit system , 64 bit simply allows you to have more than 3.2gb of ram in your system .. if you have a 32bit system installed and you have 8gb of ram in your board you will onlyu get to use 3.2gb of it..

in real plain english if you want to use more than 3.2gb of ram for a system doing heavy work then you would have to upgrade to 64bit in order to use the extra ram you install .. eg.. if you are a gamer trying to play battlefield while your downloading and converting a file in the background then you will need quiete a bit more than 3.2gb of ram, and as i said before if you want more than that amount of ram then you will 64bit. hope i was plain enough

Linus 64bit Vs 32bit http://www.youtube.com/watch?v=IknbgnJLSRY&list=UU0vBXGSyV14uvJ4hECDOl0Q

32 bit can address 2 to the power of 32 locations.. .. i.e. 4GB
that's why a 32 bit OS cant "see" more space than 4GB, so with hardware requiring some address space... and 4Gb mem 32 bit machine "sees" less than the 4GB of RAM.
64 bit can see 2 to the power of 64.. which is A LOT - so has no practical memory constraint.

HTH (rather than confuses)

32 bit software almost always runs in a 64 bit OS. We have been using 64 bit processors since around 2000. AMD had 64 bit available to public before Intel. MS tried to release a 64 bit version of XP but it didn't go over to well. So Vista was really when 64 bit started at MS. 64 bit is potentially faster and more efficient if you run 64 programs which dominate the world now. Also 32 bit software will usually run on a 64 bit OS but 64 WILL NOT run on a 32 bit OS. Basically older 16 bit software has problems running in 64 bit OS's so if you have alot of software from before 2005 32 bot may be a better pick.

Hi,

There are several major advantages to using 64 bit operating systems when compared to 32 bit operating systems. I'm going to focus exclusively on Intel x86 microprocessors for this post. The same differences will not necessarily be applicable to other microarchitectures such as ARMv7 vs ARMv8

First, x86 microprocessors operating in the 64-bit mode of operating (called long mode) has access to twice as many addressable CPU registers as when the same microprocessor is running in the 32-bit mode of operation (called protected mode); 16 registers on each stack rather than 8. This means that software compilers can be much more efficient when it comes to managing memory as data has to be swapped to and from memory less often. This increases the overall efficiency and speed of many programs.

Second, long mode extends the size of the general purpose CPU registers from 32-bits to 64-bits in size. This enables native 64-bit integer arithmetic which is much faster than emulated 64-bit integer arithmetic which is accomplished by decomposing a single 64-bit operation into multiple 32-bit operations. So not only are the CPU registers twice as numerous, but the general purpose registers are twice as wide. The advantage of this is increased speed for applications that use 64-bit integer arithmetic.

Third, long mode supports 64-bit virtual address spaces. x86 microprocessors have supported 64-bit physical address spaces since 1995 (through Physical Address Extension) which allows a microprocessor to address more than 4GiB of physical memory, usually 64GiB or 128GiB. Windows has supported PAE since Windows 2000 Server which supported up to 8GiB of physical memory. However, a single 32-bit process is still limited to a 32-bit virtual address space even when that 32-bit virtual address space is mapped to a much larger 64-bit address space. This is handy for high end servers that run many applications and services at once, but less useful for consumer machines which focus on only a few applications at a time.

Fourth, long mode is naturally more powerful. It standardizes certain microprocessor instruction set extensions and eliminates older ones which allows compilers to automatically optimize the compiled code to a greater degree while maintaining confidence that the code will run on a great number of devices.

Fifth, long mode is naturally more flexible. Many operations that were previously handled in hardware (such as task switching) are now forcibly done in software. This allows the operating system to have decide what to support and what not to.

Sixth, long mode is naturally more secure. I won't go deeply into this because it's very difficult to understand the advantage but many security holes and hardware level exploits were closed in long mode.