Do 64 bit Processors Run Older Software?

  • Thread starter Thread starter jim evans
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J

jim evans

I'm about to build a new system and 64bit processors seem to be common
now. Will these processors run any software that will run on a 32 bit
processor with the same OS?
 
Oh yes, will 64bit processors run versions of the OS that are not
64bit based (such as ordinary XP)?
 
The possibilites are:

1. 64-bit address space, meaining more memory is addressable.
2. Wider 64-bit registers, used in executing instructions.
3. Wider data paths, data can be moved to memory faster.
4. Additional registers available to the cpu for instruction execution.

.. . . but since the software is 32-bit, most of the above is not used. The
only possibility is when the CPU is moving data to and from its own cache,
perhaps that is faster.

--g
 
jim evans said:
Thanks, and one final thing.

Do the 64 bit processors provide any advantage if running a 32 bit OS?
Click to expand...

Other than being more current technology, not really. -Dave
 
Thanks, and one final thing.

Do the 64 bit processors provide any advantage if running a 32 bit OS?
Click to expand...

They run multiple programs faster than a single core processor. Think
SETI and Call of Duty Modern Warfare at the same time.

Bill
 
They run multiple programs faster than a single core processor. Think
SETI and Call of Duty Modern Warfare at the same time.
Click to expand...

I understand how dual core processors can improve speed, I was asking
about 64 bit. Maybe you're saying all dual core processors are 64
bit?
 
jim evans said:
I understand how dual core processors can improve speed, I was asking
about 64 bit. Maybe you're saying all dual core processors are 64
bit?
Click to expand...

All current consumer CPUs (Intel Socket 775 and AMD Turion/Athlon/FX) are
64-bit.

You may find a few out-of-production, 32-bit Celerons and Athlons around on
low-end machines, though...
 
I understand how dual core processors can improve speed, I was asking
about 64 bit. Maybe you're saying all dual core processors are 64
bit?
Click to expand...

32 bit x86 processors will run 32bit x86 software only. 64 bit x86
dual core processors will run 32 bit and 64 bit x86 software. They
will run multiple instances of software faster for a given clock speed
than a single processor simply because 2 processors can do more work
than one. You ask a more specific question you'll get a more specific
answer.

Bill
 
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