Confusion about what a 64-bit operating system has over 32-bit?

[RockGuitarDude]

I understand whats the differences between 32 bit and 64 bit processing, what is unclear to me is how this affects an operating system. Is it just the operating system processes that get a boost? From what I read, the current chips are engineered to be able to switch between 32 and 64 bit whenever needed, so would I be able to run a 32 bit program on a 64 bit OS or vice versa?

 

[shortylickens]

You can run a 32-bit app in a 64-bit OS.
NOT true for 64-bit programs in a 32-bit OS.
You also need a 64-bit processor.
Since the only complete 64-bit OS's are certain versions of Linux, you may have to go to some Linux forums to talk about performance increases.
Anandtechs reviews show that the performance boost is not always worth the money.

IF you mismatch 32-bit programs, OS's and processors with 64-bit versions, you do get some small benefits like: increased memory access, increased color and audio depth with less of a performance hit.
It would seem all the game and general software makers are happy with 32-bit color and 24-bit audio.

I'm using and Athlon 64 with regular 32-bit Windows XP. I did notice a BIG performance boost in just about everything. Pretty nice considering the CPU speed and FSB and memory bus all have the same clock speeds as before.

You can also look at the reviews of the new Mac with 64-bit OS and processor too. But NOT from the Apple web site. Find an independant, objective reviewer.

 

[Schadenfroh]

but does XP 64bit have a 64bit version Internet Explorer and outlooks express?

 

[iwantanewcomputer]

[q
I'm using and Athlon 64 with regular 32-bit Windows XP. I did notice a BIG performance boost in just about everything. Pretty nice considering the CPU speed and FSB and memory bus all have the same clock speeds as before.
q]

that's cause the athlon 64's core has a lot more performance ehancements over the athlon xp other than 64 bit extensions. AMD states in their roadmaps that the athlon 64 is 25% faster than athlon xp with all else the same. the performance increase you noticed has nothing to do with 64 bit-ness, just a faster processor

Originally posted by: Schadenfroh
but does XP 64bit have a 64bit version Internet Explorer and outlooks express?

Any athlon 64 does not need extra performance to do simple computing like outlook and explorer. these would barely be worth microsoft's time to reprogram with 64 bit data calculations because there is not a noticable performance difference in these programs running the slowest athlon 64 and the fastest of any processor currently available

 

[Schadenfroh]

i asked out of curiosity

 

[Nothinman]

You can run a 32-bit app in a 64-bit OS.

Not 100% true. It only works if the OS supports it and you have copies of all the 32-bit libraries around. That means double the disk space if you try to use a lot of 32-bit apps in a 64-bit environment.

Since the only complete 64-bit OS's are certain versions of Linux, you may have to go to some Linux forums to talk about performance increases.
Anandtechs reviews show that the performance boost is not always worth the money.

So Solaris, Tru64, HP-UX, FreeBSD, etc don't count?

I'm using and Athlon 64 with regular 32-bit Windows XP. I did notice a BIG performance boost in just about everything. Pretty nice considering the CPU speed and FSB and memory bus all have the same clock speeds as before.

That's just because of the way the A64 was engineered, it has nothing to do with the fact that it's a 64-bit CPU. Infact I believe one of the biggest performance boosters isn't being touched since you're using a 32-bit OS that can't use all the additional registers available in 64-bit mode.

Given all things equal, in a 100% 1:1 comparison a 64-bit application will be the same or slower because of the larger binary size among other things. Now given something like Oracle that needs tons of memory, sure a 64-bit environment can be a huge performance gain, but the apps that will see performance gains from simply being 64-bit are few and far between.