Difference between 32 and 64 ?

[Sona]

Anybody know what the difference is between 32 and 64 bit on the OS ?

[Archangel1994]

64-bit = More than 4GB of addressable RAM, able to run both 32-bit and 64-bit applications (99% of the time) and has higher performance in some aspects (Can't remember what way exactly but can make a difference on phones and slow devices)

[Sona]

64-bit = More than 4GB of addressable RAM, able to run both 32-bit and 64-bit applications (99% of the time) and has higher performance in some aspects (Can't remember what way exactly but can make a difference on phones and slow devices)

So 64 bit is better ?

[wildy]

 

Anybody know what the difference is between 32 and 64 bit on the OS ?

 

[Archangel1994]

So 64 bit is better ?

Pretty much, I'm not aware of any advantage that 32-bit might have

 

Edit: More like there is no reason to go 32-bit if you can get 64-bit

[WinNut]

A 32-bit OS can only address 4GB of RAM, that is, if you have 128GB of RAM but install a 32-bit OS you'll only be able to use 4GB of it, the rest will sit around.

 

With Windows 7, the amount of RAM that a 64-bit OS can address depends on the version you are running.

[Nineshadow]

In digital circuits, only 0's and 1's (usually low voltage and high voltage) can be transmitted from one element (CPU) to another element (memory chip). If I have only 1 wire, I can only send either a 1 or a 0 over the wire per clock cycle. This means I can only address 2 bytes (assuming byte addressing, and that entire addresses are transmitted in just 1 cycle for speed!).

 

If I have 2 wires, I can address 4 bytes. Because I can send: (0, 0), (0, 1), (1, 0), or (1, 1) over the two wires. So basically it's 2 to the power of # of wires.

 

So if I have 32 wires, I can address 4 GB, and if I have 64 wires, I can address a lot more.

 

There are other tricks that engineers can do to address a larger address space than the wires allow for. E.g. splitting up the address into two parts and sending one half in the first cycle and the second half on the next cycle. But that means that your memory interface will be half as fast.

 

At the moment 64-bits is quite a lot for addressing real physical memory. Most 64-bit CPUs will omit quite a few wires when it comes to wiring up the CPU to the memory due to practicality. It won't make sense to use up precious motherboard real estate to run wires that will always have 0's. Not to mention in order to have the max amount of RAM with today's DIMM density would require 4 billion dimm slots

 

Other than the increased amount of memory, 64-bit processors offer faster computation for integer numbers larger than 2^32. Previously programmers (or compilers, which is also programmed by programmers would have to simulate having a 64-bit register by taking up two 32-bit registers and handling any overflow situations. But on 64-bit CPUs it would be handled by the CPU itself.

 

The drawback is that a 64-bit CPU (with everything equal) would consume more power than a 32-bit CPU just due to (roughly) twice the amount of circuitry needed. However, in reality you will never get equal comparison because newer CPUs will be manufactured in newer silicon processes that have less power leakage, allow you to cram more circuit in the same die size, etc. But 64-bit architectures would consume twice as much memory. What was once considered "ugly" of x86's variable instruction length is actually an advantage now compared to architectures that uses a fixed instruction size.

-> more in-depth about 64-bit as a CPU architecture itself

 

Yeah, 64-bit is always better.There's no reason not to get it.

[AMICLG]

A 32-bit OS can only address 4GB of RAM, that is, if you have 128GB of RAM but install a 32-bit OS you'll only be able to use 4GB of it, the rest will sit around.

 

With Windows 7, the amount of RAM that a 64-bit OS can address depends on the version you are running.

Well if the OS has PAE then you can use all 128GB of RAM and be 32-bit but anything needing 128GB is likely going to need 64-bit anyway.

[SteveGrabowski]

64 bit Intel/AMD CPUs also have more registers than do 32 bit ones, and a 32 bit operating system will only be using the registers known to exist on the 32 bit CPUs (which is maybe half the number of registers on the 64 bit ones). Think of registers as tiny pieces of extremely fast memory that can be used directly for computations.