12.04 32 bit vs 64 bit.

[L Campbell]

I'm using 12.04 on a desktop PC and I wonder if there is a difference between the 32 and 64 versions, or is it a matter of what type of file system already has?

Your opinions will be appreciated.

TIA.

[kc1di]

The only real difference in 64 bit over 32 is that of the processor. if you have a 64 bit processor use 64 bit install
if not go with 32. some 64 bit programs may run a little faster than there 32 bit counterparts. but that is very subjective.

it really does not have much to do with the file system in use.

[Impavidus]

There's also a difference in RAM. 64 bit can handle more RAM, so you need it to use more than about 3GB efficiently, but at the same time any task in 64 bit will use more memory than the same task in 32 bit. So, if you have a 64 bit processor and less than 1GB of RAM it may be not such a bad idea to use 32 bit anyway. It would be a case of a CPU that's overpowered compared to the amound of RAM, in other words, a badly designed machine.

[pfeiffep]

This is a pretty straight forward explanation

[monkeybrain2012]

Definitely 64 bits if your machine supports it. It is faster and smoother and you can access all the ram.

[deadflowr]

There are a few legacy 32-bit applications that won't run.

But they are few and far between as multiarch improves and old apps get 64-bit versions.

[monkeybrain2012]

There are a few legacy 32-bit applications that won't run.
.

Haven't come across any of those, seems to be mainly a Windows problem (that applications run only in 32 bits)

Edited: so yeah maybe for some WINE stuffs,.

[kc1di]

There's also a difference in RAM. 64 bit can handle more RAM, so you need it to use more than about 3GB efficiently, but at the same time any task in 64 bit will use more memory than the same task in 32 bit. So, if you have a 64 bit processor and less than 1GB of RAM it may be not such a bad idea to use 32 bit anyway. It would be a case of a CPU that's overpowered compared to the amound of RAM, in other words, a badly designed machine.

That's not always the case if a 32 bit machine is PAE capable it can address more thatn 3 GB Ram.

[3rdalbum]

That's not always the case if a 32 bit machine is PAE capable it can address more thatn 3 GB Ram.

A 32-bit CPU can address 4 GiB of RAM, but that includes little pieces of memory outside main RAM too (graphics card memory, SATA buffer, USB buffers, Ethernet buffers etc).

A 32-bit CPU with PAE and a PAE-compatible kernel actually becomes a 36-bit CPU running 32-bit programs.

A 64-bit CPU is a 64-bit CPU.

So technically, a 64-bit CPU can still address more RAM than a 32-bit CPU, even with PAE. However, PAE can address more RAM than a desktop computer can actually physically fit!

Another advantage to 64-bit is: As the earliest 64-bit CPU that can run Ubuntu is much more modern than the earliest 32-bit CPU that can run Ubuntu, you can be assured that your 64-bit CPU includes optimizations and security features that are not guaranteed to be present on a 32-bit CPU. Therefore, the 64-bit Ubuntu kernel can safely be built to use the extra optimizations and features, but the 32-bit kernel can't. In other words the 64-bit Ubuntu kernel has extra security features.

[Paqman]

Another advantage to 64-bit is: As the earliest 64-bit CPU that can run Ubuntu is much more modern than the earliest 32-bit CPU that can run Ubuntu, you can be assured that your 64-bit CPU includes optimizations and security features that are not guaranteed to be present on a 32-bit CPU. Therefore, the 64-bit Ubuntu kernel can safely be built to use the extra optimizations and features, but the 32-bit kernel can't. In other words the 64-bit Ubuntu kernel has extra security features.

That's actually a really good point, and not one that I'd considered before.