Any advantage to running a 64bit OS on a NON 64 bit system?

[Philippine Mango]

I was wondering that since programs are not able to utilize more then 2GB of ram on 32bit systems (processors) that the only way you could fully utilize 4GB was to have two programs running at the same time. I also heard that this is a limitation of the OS and not so much the hardware so I was wondering if a 64bit OS would alleviate this issue. It would be nice if I could get this completely clarified since it's a bit confusing.

 

[tk11]

A 64 bit os wouldn't run on a 32 bit system.

 

[Nothinman]

It's a hardware limitation, a 32-bit processor can only use 32-bits for memory addressing, there's no way around that.

 

[joshc]

Originally posted by: Philippine Mango
I was wondering that since programs are not able to utilize more then 2GB of ram on 32bit systems (processors) that the only way you could fully utilize 4GB was to have two programs running at the same time.

Where'd you get this 2GB number from? A 32-bit CPU has a 4GB address space and this is a limitation of the architecture. As mentioned above you can not run a 64-bit OS on a 32-bit CPU.

 

[Philippine Mango]

I got 2GB because I heard photoshop can't utilize more than 2GB..

 

[HardcoreRobot]

i dont even know where to begin...

the largest number 32 bits can represent (and thus address) is 4294967295 (4GB)
likewise, for 64 bits, the number is 18446744073709551615 (a crapload)

 

[cleverhandle]

I think he's talking about the application memory vs. kernel memory thing - whatever it is that PAE works around.

 

[drag]

Originally posted by: cleverhandle
I think he's talking about the application memory vs. kernel memory thing - whatever it is that PAE works around.

Thats what I was thinking of too. Makes sense.

Also there maybe internal limitations to photoshop.

 

[Nothinman]

Where'd you get this 2GB number from?

In Windows each process is limited to 2G of VM, the other 2G is reserved for the kernel.

 

[user1234]

it's really funny and pathetic that everyone is asking when xp64 is going to be officially released, but no one is asking about compatibility. I guess you assume it will run your exsiting 32-bit apps just fine, right ? bzzzz, wrong ! well at least if you had the guts to try out the beta you'll see it does have problems with quite a few apps and games. For example, Aquamark3 doesn't run (tried on two machines and both RC1 and RC2), same goes for Far Cry on at least on machine, and some apps did not like to be under "Program file (x86)" because it contains special characters in the folder name. And on one machine (based on FoxConn NF4K8MC-ERS mobo) the nvidia chipset drivers caused problems - it caused many apps to crash until I uninstalled th eSMBus driver, the IDE driver and network manager (only left the essential drivers - audio, ethernet, display). So did anyone actually try out the beta and had any problems, or you all just keep talking about when it's going to be released ?

 

[drag]

Originally posted by: user1234
it's really funny and pathetic that everyone is asking when xp64 is going to be officially released, but no one is asking about compatibility. I guess you assume it will run your exsiting 32-bit apps just fine, right ? bzzzz, wrong ! well at least if you had the guts to try out the beta you'll see it does have problems with quite a few apps and games. For example, Aquamark3 doesn't run (tried on two machines and both RC1 and RC2), same goes for Far Cry on at least on machine, and some apps did not like to be under "Program file (x86)" because it contains special characters in the folder name. And on one machine (based on FoxConn NF4K8MC-ERS mobo) the nvidia chipset drivers caused problems - it caused many apps to crash until I uninstalled th eSMBus driver, the IDE driver and network manager (only left the essential drivers - audio, ethernet, display). So did anyone actually try out the beta and had any problems, or you all just keep talking about when it's going to be released ?

I think you just pointed out why it hasn't been released yet... They'd probably want to get most everything working before they release it.

 

[user1234]

right, that's what I think also, it's just that I'm surprised not to see any comments or discussions about the problems with existing apps (backward incompatibility). I mean RC1/2 is much better then what they had a year ago, when you'd be lucky to get networking drivers, but still a significant percentage of programs have issues. Anyone got aquamark3 running ?