64bit silly question

slzckboy · 01-04-2006, 07:38 AM

ok.
Maybe a programming or hardware question .
Sorry Not sure.

o.k

Say I'm running a 64 bit distro.
Obviuosly 32 bit binarys will run but not utilise the full capacity of the processor ?!??
Whe you compile a program from source will that now be compiled in a manner that will be more native to the processor enabling 64nit support ?

thnks in advance.

Lenard · 01-04-2006, 09:16 AM

Depends on the source, if it's not 64-bit compliant then it may fail.
Ask the author(s) of the source to be sure.

slzckboy · 01-04-2006, 11:27 AM

really?
so code written for i386 will not necessarily compile and run on 64bit architecture that runs a 64 bit op system?!!!

cs-cam · 01-04-2006, 06:28 PM

zomg architectures!!!1

Course not, it would be a pretty poorly written program if it didn't but thats not to say there aren't a whole lot of them out there

SciYro · 01-04-2006, 08:18 PM

very few programs even benefit from 64-bits. So, its not like they aren't using the full processor capacity, its that it doesnt need 64-bit operations to do the equivalent of 32-bit work.

take this math operation:

5x5-1+2=21

even a 8-bit processor could do that, its not like 64-bits would do much difference, when it only uses 8.

BrianK · 01-04-2006, 08:31 PM

Intel and AMD 64 bit processors have a 32bit instruction set as well. They should run/compile all 32 bit software without any issue... In theory, it will run no faster or slower than it would on a 32 bit processor of the same speed, asssuming it's not using 64 bit words or addresses (which it probably isn't).

slzckboy · 01-05-2006, 07:27 AM

Quote:

Originally Posted by BrianK

Intel and AMD 64 bit processors have a 32bit instruction set as well. They should run/compile all 32 bit software without any issue... In theory, it will run no faster or slower than it would on a 32 bit processor of the same speed, asssuming it's not using 64 bit words or addresses (which it probably isn't).

right

thats what I thought.

My collegue at work said that the architecture of these systems are different.
Thus the buses between the processor and the system are larger thus enabling data to be put through quicker.

But if an operation only asks to put write n bytes of data its only going to write n bytes of data no matter how large the bus is right ??

slzckboy · 01-05-2006, 07:50 AM

http://www.softwaretipsandtricks.com...bit-processors

just to back up what has already been said.

thnks gents