Re: Usable RAM
Paul33 wrote:
> XP Pro, SP2
>
> I have 4GB RAM. XP says not. I have read the Service Note that says
> why, but that doesn't help much. I want to assign 2GB to Photoshop,
> however, PS says that there is less than 2 available and suggest
> assigning no more than 1.232 Should I simply ignore this and assign
> 2 to PS? If not, how do I fix this?
Shenan Stanley wrote:
> Have you looked into the /3GB switch for BOOT.INI?
> How about using Windows XP x64?
> Windows Vista 64 bit?
Jim wrote:
> XP is reporting that portion of your 4 GB RAM which it can use.
> The rest gets taken by such items as shared memory on the graphics
> card and perhaps non paged pool.
>
> Of course, you can assign whatever you want, but PS will still
> complain and refuse to start.
Paul33 wrote:
> System information (General tab) gives 3.12 GB of RAM. Why? Is this
> the 3GB switch? Photoshop says that the available RAM is 1.711GB.
> What happened to the other 1.4?
>
> Surely many thousands of others (non-Mac users) have had this same
> question; is there a simple instruction to permit XP-Photoshop to
> use the actually available RAM?
>
> I read the switch article, as did my computer builder, and it seems
> to apply only to servers.
Jim wrote:
> No, it is not the /3GB switch. This switch applies to the
> allowable user virtual memory space.
> The missing RAM can be consumed by shared memory in the graphics
> card.
>
> No, you will never get to use the full 4gb virtual memory because
> the operating system must
> be mapped into the virtual address space. This statement applies
> to all virtual memory operating
> systems.
>
> The reason that PS is reporting that value is that you do not have
> the /3gb switch added. In this instance,
> the user virtual memory space is 2gb , but some of this value is
> consumed by necessary data structures.
>
> As for the switch article, you both misinterpreted it. The server
> systems include the PAE facility which
> must be enabled by the motherboard. I don't believe that any of
> the PC systems have such a motherboard.
>
> In addition, using the 3GB switch will have no effect unless the
> application supports such a change to the
> operation of the program.
Paul33 wrote:
> Thanks all. Unfortunately I remain, perhaps as always, confused. I
> thought that "virtual memory" was a specified chunk (virtual paging
> file?) of your "c" drive that windows uses as if it were RAM; but
> that installed RAM wasn't "virtual."
>
> Photoshop literature says it can use 2GB of RAM (32 bit) and will
> run most efficiently with that much RAM assigned. XP literature
> says it can use (address?) 4GB. My last computer ran XP and PS on
> 1GB.
>
> Is there software available that will help one assign the installed
> RAM (no more than 4GB) as "you" want, rather than it being assigned
> by some non-transparent internal operation that hardly seems
> efficient? Is there an article on changing the boot.ini file with
> any pros and cons?
Virtual Memory is a chunk of your hard disk drive space that is used for
paging operations or temporary 'fake' memory. It's performance is no better
than the performance of the hard disk drive - which is MUCH slower than your
actual memory. Virtual memory/Page File is NOT a substitute for actual RAM.
The limitation of 4GB in Windows XP (non-64 bit) has more to do with the
ability of a 32 bit systems ability to access that much RAM than anything
else. It has been pointed out to you that you need to edit your BOOT.INI
and add the /3GB switch in order to give more to the applications and less
to the operating system (in laymans terms.)
With that /3GB switch - perhaps Photoshop *will* utilize 2GB of RAM - but it
will likely only pull that much in *when it needs it* - and not just reserve
it for itself. At least - that would make more sense.
You are better off adding the /3GB switch in BOOT.INI and trying it out and
seeing if that makes any noticable performance difference in Photoshop than
continuing to worry over this much more. (If there is software - it would
be messing with native Windows Memory Management functions - and who knows
what that would do to stability. Sure- maybe you could squeeze 2.5GB of
your memory and assign it to photoshop - but would it be worth the machine
randomly rebooting before you had a chance to save?)
Your other option - make sure your version of Photoshop will run in Windows
XP x64, make sure all your hardware has drivers from Windows XP x64 (and any
other software you plan on using with it works in x64 as well) and install
Windows XP x64. Then you could have 8GB+ of memory if you want and it will
be better managed.
As for your computer builder's kknowledge of computers - you may want to
allow them to continue building your systems (hardware) - but get yourself
someone else for software/operating system advice... *grin*
Use these instructions to add the /3GB to your Windows XP boot.ini file:
http://searchwincomputing.techtarget.com/tip/0,289483,sid68_gci1108831,00.html
Some advice on the /3GB switch in the BOOT.INI:
It will not *make* Windows XP show you that you have 4GB of physical
memory - in fact - Windows XP 32-bit will *never* show you that you have 4GB
of memory. It could even degrade performance of Windows XP itself -
although, not usually as the 1GB is more than enough for the OS and its
needs. It just forces the OS to allocate 3GB to the programs and only 1GB
to the system.
--
Shenan Stanley
MS-MVP
--
How To Ask Questions The Smart Way
http://www.catb.org/~esr/faqs/smart-questions.html
4D262FB-DB17-49EA-8720-430D9C52F8BE@microsoft.com...
, but most often