David,
Correct me if I'm wrong, but I think you are talking about 32 bit vs. 64 bit processors (that is, hardware)
I believe Phil was referring to 32 bit vs. 64 bit Windows.
Not to say that you are wrong, but I think we need to clarify which we are talking about.
As example, your statement "32 bit machines support up to 64 GB of RAM
"... may be true (I don't know), but this 32 bit Windows I'm running only supports 3+ GB.
It's the difference between 32/64 bit processors and 32/64 bit software, and for the benefit of those who don't recognize the difference, perhaps we should be state of which we speak?
rogerX
--- In simplycomputers2@yahoogroups.com, David Ron <david.m.ron@...> wrote:
>
> Sorry... I'm going to make a few corrections....
>
> A 32 bit system has, for fear of oversimplifying, a set of 32 wires that wind their way through the CPU to process instructions. This means that each clock cycle can handle 32 bits of data in each clock cycle (not counting the fact that a CPU can sometimes execute more than one instruction in a cycle). A 1 Ghz processor has 1 billion clock cycles in a second.
>
> In theory, A 64 bit system has 64 wires and therefore can handle twice as much data in a clock cycle. In fact, this is not precisely true because of the way that instructions are processed, a 64 bit system can only really handle less than 30% more data.
>
> There is a common misconseption that a 32-bit system can only address 2^32 bytes of memory which works out to 4 billion bytes, or 4gb of RAM. In truth, 32-bit systems have had support for PAE since the mid 1990s which allows them to support 36 bits of data, which is 2^36=64GB of RAM. The 4GB limitation on 32-bit machines is an artificial limitation in Windows that Microsoft has put into place to make people pay a little more for 64-bit support. I have 16GB of RAM in my 32bit Ubuntu installation that works fine.
>
> It is true that in theory, a 64-bit machine can process data faster than a 32-bit machine because there is more room to fit the instruction and the location in RAM that the instruction is supposed to take place encoded in a single 64-bits and therefore save a clock cycle or two by doing the fetching of the data and the math on that data in a single instruction. Fortunately for us 32-bit users this is also incorrect. All CPUs have an instruction pipeline that can pre-fetch data before executing the instruction and so adding the extra bits really doesn't make a difference. In fact, since there are more transistors in a 64-bit chip than a 32-bit chip, and you have to wait for all of the wires to finish before moving on to the next instruction, some 64-bit chips are actually slower (in Ghz) than their 32-bit counterparts - or they can't be overclocked as much.
>
> The only place where there is more than a nominal difference in speed is when you are crunching extremely large integers or you need a single application to use more than 2GB of RAM. Only people who are rendering video (Pixar) or doing complex scientific calculations (NASA) would notice the difference.
>
> In other words:
>
> 1. 64 bit machines aren't noticeably faster than 32 bit machines.
> 2. 32 bit machines support up to 64 GB of RAM
> 3. Microsoft has placed an artificial limitation of 4GB on 32 bit windows.
>
>
> --David
>
>
>
> On 11/27/2011 09:27 AM, Ardell Faul wrote:
> >
> > A 32 bit system can handle 2 to the 32nd power, or 429,4967,296 bits of
> > data in each clock cycle.
> >
> > a 64 bit system can handle 2 to the 64th power, or
> > 18,446,744,073,709,551,616. A BIG difference.
> >
> > Ardell Faul
> > Computer Monitor Service Inc.
> > Ardell's Laptop and PC Repair
> > 10816 E. Mission Ave.,
> > Spokane Valley, Wa. 99206
> > ardell@... <mailto:ardell%40icehouse.net>
> > 509-891-5188
> >
> > On 11/26/2011 11:07 PM, Phillip and Joyce wrote:
> > >
> > > I see some programs run on 32 or 64 bit.
> > > What is the differences and how can you tell what one you have?
> > > Phil
> > >
> > >
> >
> > [Non-text portions of this message have been removed]
> >
> >
>
>
> [Non-text portions of this message have been removed]
>
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