64-bit OS, WINE and Memory (size) related question.

[imatechguy]

Having avoided them for some time now, based on compatibility concerns as I began to learn and use Linux full time, I’ve recently gotten the urge to start playing around with some 64-bit distro’s. The benefit of course is running more than the 4Gb (system-wide) limit imposed by a 32-bit OS. In my current system I only have 2Gb (2x1Gb) of RAM so I’m thinking of either adding 4Gb (2x2Gb) or even upgrading to 8Gb (4x2Gb). My dilemma is that the apps I use WINE for (Games) are all 32-bit, which leaves me to wonder how effectively used the extra memory will be utilized, by both the OS and WINE. Something else that gives me pause is that in searching for an existing answer I saw quite a few posts/threads related to WINE and how it reserves memory/virtual memory regardless. I would appreciate any insight, links to benchmarking data, etc. available.

Thanks

[vitamin]

Wine being a 32-bit program can not use more then 4GB at a time. Neither can 32-bit windows programs. In reality it's even less then 4GB (maximum is around 3 .. 3.5).

The extra RAM is always beneficial to a system performance one way or the other. So having more memory then Wine knows what to do with will still help other parts of the system to run better/faster.

[L. Rahyen]

On 2009-05-13 (Wednesday) 18:23:07 imatechguy wrote:

I've recently gotten the urge to start playing around with some 64-bit
distros.
...
My dilemma is that the apps I use WINE for (Games) are all 32-bit, which
leaves me to wonder how effectively used the extra memory will be utilized,
by both the OS and WINE.

64-bit Linux will use all available memory in your computer very well. You can
expect much better performance after adding more memory if now you are using
swap. Run "top" to see how much swap you are using; if more than 0 then adding
more memory to your computer is good idea and you can expect better
performance. Even if you have zero swap usage additional memory can be used by
Linux for caching and buffers to improve performance.
However, 64-bit Linux kernel or Wine can't do anything to remove 32-bit
limitations from 32-bit applications (vitamin already explained these
limitations to you).

[imatechguy]

Wine being a 32-bit program can not use more then 4GB at a time. Neither can 32-bit windows programs. In reality it's even less then 4GB (maximum is around 3 .. 3.5).

The extra RAM is always beneficial to a system performance one way or the other. So having more memory then Wine knows what to do with will still help other parts of the system to run better/faster.

Yep, totally on board with the memory addressing limitation of a 32-bit system and/or program. Actually that's kind of what spawned my post. Being as there is that limitation how effective will Linux and WINE be at "sharing" the available memory and given some of the posts regarding how WINE allocates virtual memory would it even be beneficial having more than 2-4Gb?

L.Rahyen touched on this but lets say for example I have 8Gb of RAM. 64-bit Linux boots up and goes nuts filling as much as it can. Now I load up a game using WINE. If I have 1 full Gig of non-RAM system memory(GPU, Sound Card, etc.), then WINE should only be able to use 3Gb of RAM regardless of how much is available. So does WINE get as much as it can use from my Linux distro or just whats available that Linux hasn't yet gobbled up? I realize that's rather oversimplified but it's the best way to explain what I'm thinking.

I did run top as suggested and it showed that even with just my current 2Gb of RAM I was only using 88-92k of Swap before and after loading NWN2 and I still had a good bit over 300,000k of RAM available. Before you ask, yes - I loaded past the menu screens and actually into a saved game file.

Thoughts?

[Gert van den Berg]

On Wed, May 13, 2009 at 20:23, imatechguy <[email protected]> wrote:

Having avoided them for some time now, based on compatibility concerns as I began to learn and use Linux full time, I’ve recently gotten the urge to start playing around with some 64-bit distro’s.  The benefit of course is running more than the 4Gb (system-wide) limit imposed by a 32-bit OS.

Actually, 32-bit operating systems can use up to 64GB of RAM on CPU's
with PAE (Any CPU newer than a Pentium Pro basically). A single
applicataion can only see 4GB at a time though. Linux and certain
32-bit Windows Server versions support PAE.

The main benefit of 64-bit mode on the CPUs are 64-bit registers and a
large amount of new registers. For quite a few algorithms, this might
significantly decrease the amount of meemory access that is needed,
which may speed it up a bit. (Whether this is relevant, depends a lot
on the application, and it is only applicable for 64-bit applications)

The 64-bit compatibility under Linux is a lot better under Linux than
windows, probably because Linux is quite widely used on several older
64-bit architectures (Aplha, PowerPC 64, SPARC V6, IA-64, etc) and
portability of code were taken into account a lot more. Having the
source code helps as well. The lack of consideration to compatibility
issues (by driver devolopers) also caused windows XP to stop
supporting using the full 4GB of RAM using PAE. See here for details:
http://support.microsoft.com/kb/888137

 In my current system I only have 2Gb (2x1Gb) of RAM so I’m thinking of either adding 4Gb (2x2Gb) or even upgrading to 8Gb (4x2Gb).  My dilemma is that the apps I use WINE for (Games) are all 32-bit, which leaves me to wonder how effectively used the extra memory will be utilized, by both the OS and WINE.  Something else that gives me pause is that in searching for an existing answer I saw quite a few posts/threads related to WINE and how it reserves memory/virtual memory regardless.  I would appreciate any insight, links to benchmarking data, etc. available.

Each application (possibly rather wineserver for Wine applications)
instance should be able to use its own ~4GB on a 64-bit OS. (Wine uses
one wineserver per WINEPREFIX IIRC.)

Gert