Photoshop 7, CS and 4 GB RAM – problem

It is a limitation of the OS. From what I understand, you can tell the OS to allow 3GB of RAM for user-mode memory space by using the /3GB switch in boot.ini http://support.microsoft.com/default.aspx?scid=kb;en-us;291988 http://support.microsoft.com/default.aspx?scid=kb;en-us;289022

Remember to back up before doing anything like that.

Do a search in google to make sure I am saying the right thing before trying it.

Andrew

From: (Henrik2000)

Hello. Now i upgraded to 4 GB RAM … But Photoshop 7
and Photoshop CS only see 2 GB

According to Chris Cox and one other Adobe designer Photoshop 7 and earlier will only recognize 2 GB of RAM or less (not sure about CS, but from your post I’d say it has the same limit).

Bill

On 29 Oct 2003 05:50:55 -0800, (Henrik2000) wrote:

Hello. Now i upgraded to 4 GB RAM (with Win XP Pro SP 1). Task Manager and several softwares tell me there are 4 GB RAM inside the machine. But Photoshop 7 and Photoshop CS only see 2 GB, as i can see from the "scratch sizes" display in the status bar. When i use "Help/System info", i get this information:

Built-in memory: 2048 MB
Free memory: 2048 MB
Memory available to Photoshop: 1778 MB
Memory used by Photoshop: 80 %

Also, now when i open just one small file of 1 MB and do nothing, Photoshop’s scratch size line says "590 M/1,34 G". So Photoshop says it needs 590 MB RAM right from the start. Why?

Do you know how i can bring Photoshop to use all 4 GB RAM? Is a Ramdisk helpful?

Application processes are limited to a size of 2GB per in workstation versions of Windows. You can extend this to 3GB in the server versions but even then the application itself would need to know about that.

If you have more actual RAM than 2 GB this is a benefit if you are running more than one memory hungry program (Photoshop, Premiere, Acrobat, Acrobat Reader6, so many Adobe products here…).

A propos: With my new 4 GB RAM i set the virtual files of Windows XP to 4 GB on drive C (4 GB min, 4 GB max). Is that a good setting, from a photoshopper’s viewpoint? Photoshop gets enough scratch discs on other partitions.

Without special care for photoshop, having a large, unfragmented pagefile is a good thing and if you have the diskspace, setting it to the maximum you expect to use avoids delays for pagefile expansion and later fragmentation.

Photoshop, coming from systems without virtual memory, does its own memory management and swapping on the scratch disks and should not be affected in any way by pagefile size as long as it is big enough to allow Windows to page out all other apps.

Michael

Henrik2000 wrote:

Hello. Now i upgraded to 4 GB RAM (with Win XP Pro SP 1). Task Manager and several softwares tell me there are 4 GB RAM inside the machine. But Photoshop 7 and Photoshop CS only see 2 GB, as i can see from the "scratch sizes" display in the status bar. When i use "Help/System info", i get this information:

Built-in memory: 2048 MB
Free memory: 2048 MB
Memory available to Photoshop: 1778 MB
Memory used by Photoshop: 80 %

Also, now when i open just one small file of 1 MB and do nothing, Photoshop’s scratch size line says "590 M/1,34 G". So Photoshop says it needs 590 MB RAM right from the start. Why?

Do you know how i can bring Photoshop to use all 4 GB RAM? Is a Ramdisk helpful?

A propos: With my new 4 GB RAM i set the virtual files of Windows XP to 4 GB on drive C (4 GB min, 4 GB max). Is that a good setting, from a photoshopper’s viewpoint? Photoshop gets enough scratch discs on other partitions.

Thank you for all hints!

Welcome to the wonderful world of Windows! Two gigabytes is the maximum for a user process.

Why? Windows needs the rest for viruses, worms, patches, and spam.

—- Paul J. Gans

Hello, thanks for your useful hints. I’d thought 4 GB RAM is gorgeous for Photoshop, but now i know it doesn’t even care for it. Funny, that Adobe does limit its software like that.
Btw, yes, Photoshop 7 and Photoshop CS do behave very similar in ignoring any memory above 2 GB.

(Henrik2000) writes:

Hello, thanks for your useful hints. I’d thought 4 GB RAM is gorgeous for Photoshop, but now i know it doesn’t even care for it. Funny, that Adobe does limit its software like that.

No, Adobe doesn’t. Intel and Microsoft do.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

I suspect both Microsoft and even to some lesser extent Intel felt that it would be many years before most consumers hit the 2GB wall. I don’t think anything of them saw far enough in to the future to think that you can get 1GB of RAM for less than $100.

Robert

"Stephen H. Westin" <westin*> wrote in message

(Henrik2000) writes:

Hello, thanks for your useful hints. I’d thought 4 GB RAM is gorgeous for Photoshop, but now i know it doesn’t even care for it. Funny, that Adobe does limit its software like that.

No, Adobe doesn’t. Intel and Microsoft do.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

Err, no, it uses the upper 2GB for itself. That area of memory is where all of the OS resides.
Jim

Why? Windows needs the rest for viruses, worms, patches, and spam.

—- Paul J. Gans

On Thu, 30 Oct 2003 15:52:12 -0800, "nospam"
wrote:

I suspect both Microsoft and even to some lesser extent Intel felt that it would be many years before most consumers hit the 2GB wall. I don’t think anything of them saw far enough in to the future to think that you can get 1GB of RAM for less than $100.

Remember people laughing about those specifying "reasonable limitations" in the coputer environment?

Wasn’t it Bill Gates who thought 640KB was a reasonable limit for PC main memory?

History repeats and in IT the world moves fast enough to enable some people to repeat their errors themselves.

Michael

Robert

"Stephen H. Westin" <westin*> wrote in message

(Henrik2000) writes:

Hello, thanks for your useful hints. I’d thought 4 GB RAM is gorgeous for Photoshop, but now i know it doesn’t even care for it. Funny, that Adobe does limit its software like that.

No, Adobe doesn’t. Intel and Microsoft do.

—
-Stephen H. Westin
Any information or opinions in this message are mine: they do not represent the position of Cornell University or any of its sponsors.

Henrik2000 wrote:

Hello, thanks for your useful hints. I’d thought 4 GB RAM is gorgeous for Photoshop, but now i know it doesn’t even care for it. Funny, that Adobe does limit its software like that.
Btw, yes, Photoshop 7 and Photoshop CS do behave very similar in ignoring any memory above 2 GB.

It is NOT a Photoshop problem. It is a limitation in Windows.

Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

—- Paul J. Gans

wrote:

Err, no, it uses the upper 2GB for itself. That area of memory is where all of the OS resides.
Jim

Why? Windows needs the rest for viruses, worms, patches, and spam.

—- Paul J. Gans

Sorry. I left out the smiley face. With it you see that what you wrote and what I wrote are the same…

😉 <— note smiley.

—- Paul J. Gans

PS: The OS does not need 2 GB. It is much smaller than that. What it does reflect is the decision to limit user processes to a maximum of 2 GB.

User processes have to be limited to some amount or they could grab all of available memory. And if the user then asked the OS to do anything else, like open a browser or whatever, there’d be no memory left for the OS to even create a cryptic error message.

There are other ways to handle this situation such as reserving a fraction of memory for the OS (some OS’s do this), but most do have an upper limit for user processes.

As someone else has already noted, 2GB was thought to be more than enough at the time the decision was made.

— Paul J. Gans

From: Paul J Gans

It is NOT a Photoshop problem. It is a limitation in Windows.
Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

Does the Mac version have this same limitation?

Bill

"nospam" wrote in message

I suspect both Microsoft and even to some lesser extent Intel felt

that it

would be many years before most consumers hit the 2GB wall. I don’t

think

anything of them saw far enough in to the future to think that you can

get

1GB of RAM for less than $100.

The 2GB application address space limit in Win32 comes from the fact that Windows NT, the first 32-bit windows system, was developed on a MIPS processor and that processor at the time partitioned user and supervisor memory into 2GB parts.

Norman

By default in Win32, 32-bit Windows, a process has at most 2GB of address space to work with. This limit can be moved to 3GB in some versions of Windows. Having 4GB of RAM will still be useful since the OS uses a bunch of RAM for things.

Norman

"Henrik2000" wrote in message

Hello. Now i upgraded to 4 GB RAM (with Win XP Pro SP 1). Task Manager and several softwares tell me there are 4 GB RAM inside the machine. But Photoshop 7 and Photoshop CS only see 2 GB, as i can see from the "scratch sizes" display in the status bar. When i use "Help/System info", i get this information:

Built-in memory: 2048 MB
Free memory: 2048 MB
Memory available to Photoshop: 1778 MB
Memory used by Photoshop: 80 %

Also, now when i open just one small file of 1 MB and do nothing, Photoshop’s scratch size line says "590 M/1,34 G". So Photoshop says it needs 590 MB RAM right from the start. Why?

Do you know how i can bring Photoshop to use all 4 GB RAM? Is a Ramdisk helpful?

A propos: With my new 4 GB RAM i set the virtual files of Windows XP to 4 GB on drive C (4 GB min, 4 GB max). Is that a good setting, from a photoshopper’s viewpoint? Photoshop gets enough scratch discs on other partitions.

Thank you for all hints!

In article <TzEob.10453$>,
"Norman Black" wrote:

By default in Win32, 32-bit Windows, a process has at most 2GB of address space to work with. This limit can be moved to 3GB in some versions of Windows. Having 4GB of RAM will still be useful since the OS uses a bunch of RAM for things.

So how with PS CS behave under OS-X? Same limit?

Bill Hilton wrote:

From: Paul J Gans

It is NOT a Photoshop problem. It is a limitation in Windows.
Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

Does the Mac version have this same limitation?

I don’t know, but I’d love to be told.

— Paul J. Gans

On Sat, 01 Nov 2003 01:58:18 GMT, "Norman Black" wrote:

"nospam" wrote in message

I suspect both Microsoft and even to some lesser extent Intel felt

that it

would be many years before most consumers hit the 2GB wall. I don’t

think

anything of them saw far enough in to the future to think that you can

get

1GB of RAM for less than $100.

The 2GB application address space limit in Win32 comes from the fact that Windows NT, the first 32-bit windows system, was developed on a MIPS processor and that processor at the time partitioned user and supervisor memory into 2GB parts.

Yes, I know. I worked at a company making MIPS based NT workstations. But WindowsNT contained a thing called HAL (Hardware Abstraction Layer) to overcome processor specific design issues and more.

This worked fine for other things (bigendian and littleendian differences between MIPS and Intel architecture) so memory limits are a design decision – like the decision to load system processes memory at the highest adresses first and user processes lowest addresses first. They could have used the existing MMU in the MIPS systems for process specific memory access rights but there was nothing similar in the Intel system available at that time so decision was made to implement access rights by process address location.

And now, almost ten years later, there are restrictions in a current Windows version that come from a platform that isn’t supported for more than 5 years and two major versions.

Michael

Norman

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

Chris

In article ,
Henrik2000 wrote:

Hello. Now i upgraded to 4 GB RAM (with Win XP Pro SP 1). Task Manager and several softwares tell me there are 4 GB RAM inside the machine. But Photoshop 7 and Photoshop CS only see 2 GB, as i can see from the "scratch sizes" display in the status bar. When i use "Help/System info", i get this information:

Built-in memory: 2048 MB
Free memory: 2048 MB
Memory available to Photoshop: 1778 MB
Memory used by Photoshop: 80 %

Also, now when i open just one small file of 1 MB and do nothing, Photoshop’s scratch size line says "590 M/1,34 G". So Photoshop says it needs 590 MB RAM right from the start. Why?

Do you know how i can bring Photoshop to use all 4 GB RAM? Is a Ramdisk helpful?

A propos: With my new 4 GB RAM i set the virtual files of Windows XP to 4 GB on drive C (4 GB min, 4 GB max). Is that a good setting, from a photoshopper’s viewpoint? Photoshop gets enough scratch discs on other partitions.

Thank you for all hints!

In article <011120032126478164%>, Chris Cox
wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

Either platform – what platforms? Unix and WindoZe?

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

From: (jjs)

Either platform – what platforms? Unix and WindoZe?

Windows and Mac … Photoshop 7 wasn’t ported to Unix.

In article ,
(Bill Hilton) wrote:

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

From: (jjs)

Either platform – what platforms? Unix and WindoZe?

Windows and Mac … Photoshop 7 wasn’t ported to Unix.

Gosh this gets confusing. Mac OS-X _is_ Unix.

(Bill Hilton) wrote in
news::

From: Paul J Gans

It is NOT a Photoshop problem. It is a limitation in Windows.
Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

Does the Mac version have this same limitation?

Yes. Of course, until the advent of OS X, MacOS machines had a limit of
1.5GB. OSX raised this to 2. Why, I have no idea.

OSX for the G5 raises this to at least 8GB, the limit of the hardware, but apps have to be re-coded to recognize it, AFAICT.

My point being it’s only been relatively recently that this was actually a limitation.

(jjs) wrote in 251.sprint-rev.hbci.com:

In article ,
(Bill Hilton) wrote:

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

From: (jjs)

Either platform – what platforms? Unix and WindoZe?

Windows and Mac … Photoshop 7 wasn’t ported to Unix.

Gosh this gets confusing. Mac OS-X _is_ Unix.

No. It has a base of Unix, upon which many other things are built which Photoshop relies on.

(jjs) wrote

Gosh this gets confusing. Mac OS-X _is_ Unix.

All I can say is "Grep Awk Sed"

(If these are valid OS-X commands then I guess it’s getting close 🙂 Until then …

Bill

In article , Eric Gill
wrote:

(jjs) wrote in 251.sprint-rev.hbci.com:

Gosh this gets confusing. Mac OS-X _is_ Unix.

No. It has a base of Unix, upon which many other things are built which Photoshop relies on.

So what you are saying is that while OS-X is Unix (and it is), that PS runs through an emulator, pcode, something like that which also presumes a 32-bit architecture regardless of what might really be there?

Man I do miss the days when code was cut for specific architectures, critical routines were in-line assembler, where software spent most of its time doing real work rather than jumping through it’s own asshole via an emulator.

In article , jjs
wrote:

In article , Eric Gill
wrote:

(jjs) wrote in 251.sprint-rev.hbci.com:

Gosh this gets confusing. Mac OS-X _is_ Unix.

No. It has a base of Unix, upon which many other things are built which Photoshop relies on.

So what you are saying is that while OS-X is Unix (and it is), that PS runs through an emulator, pcode, something like that which also presumes a 32-bit architecture regardless of what might really be there?

Nobody said anything like that.

Photoshop is 100% native PowerPC code, as is OS X.

Chris

jjs wrote:

In article <011120032126478164%>, Chris Cox
wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

Either platform – what platforms? Unix and WindoZe?

Since as far as I know Photoshop only runs on Macs and PC’s, I assume that the reference is to Windows and OS X.

However, I don’t understand why OS X itself would have any such limitation as its underlying operating system has no inherent limitation.

—- Paul J. Gans

In article <021120031800359654%>, Chris Cox
wrote:

Nobody said anything like that.

Photoshop is 100% native PowerPC code, as is OS X.

Thanks, Chris. That’s good to know.

jjs wrote:

In article ,
(Bill Hilton) wrote:

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

From: (jjs)

Either platform – what platforms? Unix and WindoZe?

Windows and Mac … Photoshop 7 wasn’t ported to Unix.

Gosh this gets confusing. Mac OS-X _is_ Unix.

Yeah, but the important thing is the graphical interface. Photoshop sort of needs one… 😉

The standard graphical interface for Unix is X Windows,
a rather old and somewhat dated standard.

OS X doesn’t normally use it though I’d bet it runs on
the underlying operating system.

—- Paul J. Gans

Eric Gill wrote:

(Bill Hilton) wrote in
news::

From: Paul J Gans

It is NOT a Photoshop problem. It is a limitation in Windows.
Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

Does the Mac version have this same limitation?

Yes. Of course, until the advent of OS X, MacOS machines had a limit of
1.5GB. OSX raised this to 2. Why, I have no idea.

OSX for the G5 raises this to at least 8GB, the limit of the hardware, but apps have to be re-coded to recognize it, AFAICT.

My point being it’s only been relatively recently that this was actually a limitation.

Yes, I understand. I was just surprised that Photoshop *new* version wasn’t coded to simply ask the OS what the limit was.

As far as I remember there is no inherent limitation on
user space in the BSD Unixes. Of course, NO operating
system will let you have all of memory as it wisely retains a portion for itself so that you can ask it to kill the gargantuan user process if need be.

—- Paul J. Gans

Eric Gill wrote:

(jjs) wrote in 251.sprint-rev.hbci.com:

In article ,
(Bill Hilton) wrote:

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

From: (jjs)

Either platform – what platforms? Unix and WindoZe?

Windows and Mac … Photoshop 7 wasn’t ported to Unix.

Gosh this gets confusing. Mac OS-X _is_ Unix.

No. It has a base of Unix, upon which many other things are built which Photoshop relies on.

I agree. I’d say that the operating system *is* unix, but the graphical interface is one specially developed by Apple. That’s the most important thing for Photoshop. If Photoshop on the Mac used X-Windows two things would happen. It would run almost unchanged on many PC-based unix systems *and* we would all get old waiting for things to happen on such systems. X-Windows can be very very slow in comparison to more modern graphical interfaces.

—- Paul J. Gans

Bill Hilton wrote:

(jjs) wrote

Gosh this gets confusing. Mac OS-X _is_ Unix.

All I can say is "Grep Awk Sed"

(If these are valid OS-X commands then I guess it’s getting close 🙂 Until then …

They are valid OS-X commands. But to use them you have to open a command window. The normal Mac user is shielded from such things. But there is a full BSD unix under the hood and, on the operating system disks, there is the full set of unix compilers, tools, and other assorted stuff.

It is one reason why it is getting rather popular with the folks who use scientific workstations from Sun, SGI, etc.

—- Paul J. Gans

jjs wrote:

In article , Eric Gill
wrote:

(jjs) wrote in 251.sprint-rev.hbci.com:

Gosh this gets confusing. Mac OS-X _is_ Unix.

No. It has a base of Unix, upon which many other things are built which Photoshop relies on.

So what you are saying is that while OS-X is Unix (and it is), that PS runs through an emulator, pcode, something like that which also presumes a 32-bit architecture regardless of what might really be there?

Man I do miss the days when code was cut for specific architectures, critical routines were in-line assembler, where software spent most of its time doing real work rather than jumping through it’s own asshole via an emulator.

NO! It does not use an emulator. Photoshop has to be rewritten for the Mac to use the appropriate graphical interface calls and to use the appropriate system calls such as those for opening files. It is a large job, but straightforward. I daresay that for many of the calls a simple name change sufficed.

—- Paul J. Gans

The limitation comes from using 32 bit pointers.
Even BSD is normally limited to 2 Gig per process.

OS X had a 2 Gig/process limit, and that was increased to 4 Gig/process when the G5 shipped — but that was far too late for Photoshop CS to be tested against the new OS (and a change like that will require a LOT of testing — too many new programmers assume that pointers can be casted in and out of signed 32 bit values (sigh)).

You cannot address more than 4 Gig/process without going to pointers with more than 32 bits. And OS X is not yet completely 64 bit clean.

Chris

In article <bo4e8c$ddl$>, Paul J Gans
wrote:

Eric Gill wrote:

(Bill Hilton) wrote in
news::

From: Paul J Gans

It is NOT a Photoshop problem. It is a limitation in Windows.
Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

Does the Mac version have this same limitation?

Yes. Of course, until the advent of OS X, MacOS machines had a limit of
1.5GB. OSX raised this to 2. Why, I have no idea.

OSX for the G5 raises this to at least 8GB, the limit of the hardware, but apps have to be re-coded to recognize it, AFAICT.

My point being it’s only been relatively recently that this was actually a limitation.

Yes, I understand. I was just surprised that Photoshop *new* version wasn’t coded to simply ask the OS what the limit was.
As far as I remember there is no inherent limitation on
user space in the BSD Unixes. Of course, NO operating
system will let you have all of memory as it wisely retains a portion for itself so that you can ask it to kill the gargantuan user process if need be.

—- Paul J. Gans

Chris Cox wrote:

The limitation comes from using 32 bit pointers.
Even BSD is normally limited to 2 Gig per process.

Why? A 32 bit pointer can address 4 gigs.

OS X had a 2 Gig/process limit, and that was increased to 4 Gig/process when the G5 shipped — but that was far too late for Photoshop CS to be tested against the new OS (and a change like that will require a LOT of testing — too many new programmers assume that pointers can be casted in and out of signed 32 bit values (sigh)).

Ok. That I can understand. Except that being mean and
nasty I’d call them undereducated instead of new.

So I’m now in full agreement with you.

You cannot address more than 4 Gig/process without going to pointers with more than 32 bits. And OS X is not yet completely 64 bit clean.

Hmmm. I understood that several of the BSD’s are though. I believe that linux is, but that’s another story.

But it won’t be long now. I’m sure that the next version of Photoshop will not only run on a 64 bit processor but that it will be at least three years before we run up against a memory limit again… 😉 (And yes, I know that the full 64 bits is not addressable in some of the current interface designs. But even so…)

—- Paul J. Gans

In article <021120031838095647%>, Chris Cox
wrote:

The limitation comes from using 32 bit pointers.
Even BSD is normally limited to 2 Gig per process.

OS X had a 2 Gig/process limit, and that was increased to 4 Gig/process when the G5 shipped — but that was far too late for Photoshop CS to be tested against the new OS (and a change like that will require a LOT of testing — too many new programmers assume that pointers can be casted in and out of signed 32 bit values (sigh)).

You cannot address more than 4 Gig/process without going to pointers with more than 32 bits. And OS X is not yet completely 64 bit clean.

Ah, at long last, the definitive statement! That’s what we need to hear. Okay, I’m happy knowing where it stands, and I look forward to PS CS, and in the future, when Adobe finds all is right, massive RAM capability.

(jjs) wrote in 251.sprint-rev.hbci.com:

In article <021120031838095647%>, Chris Cox
wrote:

The limitation comes from using 32 bit pointers.
Even BSD is normally limited to 2 Gig per process.

OS X had a 2 Gig/process limit, and that was increased to 4 Gig/process when the G5 shipped — but that was far too late for Photoshop CS to be tested against the new OS (and a change like that will require a LOT of testing — too many new programmers assume that pointers can be casted in and out of signed 32 bit values (sigh)).

You cannot address more than 4 Gig/process without going to pointers with more than 32 bits. And OS X is not yet completely 64 bit clean.

Ah, at long last, the definitive statement! That’s what we need to hear. Okay, I’m happy knowing where it stands, and I look forward to PS CS, and in the future, when Adobe finds all is right, massive RAM capability.

I’ll second that (third if I’m reading Paul aright). Thanks, Chris.

Good job on PS/CS, BTW. I sat down at a client’s box yesterday, armed with a portable FW drive full of overly massive files, ran through every new feature I could find reference to on the web and about the only thing to complain about is a bit of occasional sluggishness as compared to v.7 from time to time. Considering all that went into the new release, kudos.

"Xalinai" wrote in message

But WindowsNT contained a thing called HAL (Hardware Abstraction Layer) to overcome processor specific design issues and more.

This worked fine for other things (bigendian and littleendian differences between MIPS and Intel architecture) so memory limits are a design decision – like the decision to load system processes memory at the highest adresses first and user processes lowest addresses first. They could have used the existing MMU in the MIPS systems for process specific memory access rights but there was nothing similar in the Intel system available at that time so decision was made to implement access rights by process address location.

Well according to the R4000 processor manual I have there is no choice in the matter. User mode is 2G and supervisor mode is 2GB. In fact the first .5GB or supervisor mode address space is non paged memory and uncached memory. The next .5GB is non paged memory but can be cached. The final 1GB of supervisor mode address space is normal paged and cached memory.

Of course the IA-32 processor had no hardwired limits like the MIPS processor, but MS apparently decided to keep things consistent and designed the system memory maps the same for all Win32 systems (NT based at least). For example, all of the system DLLs are loaded a known addresses at the top of the user address space. The non pages pool is in a certain address range. etc… Of course even this does not stop anything and MS has allowed certain versions of the server variant of NT to provide 3GB of address space to processes. Unfortunately MS has not let the
consumer versions of NT have a 3GB user mode address space. You cannot have 4GB of address space because NT is fundamentally designed such that kernel mode code has direct addressibility to user mode memory. For example Linux can be built such that the "kernel" swaps address space when it is called so it takes no address space away from the process. Of course this incurs some additional overhead. Typically Linux operates with a 3GB user address space.

I am well aware of the HAL but it has no ability to overcome a hardwired processor. Basically least common denominator choices are made and you then move forward from there without looking back. The HAL does abstract concepts like "setup an interrupt vector" which varies by processor. This is basically the things that the HAL abstracts. Also Windows is fundamentally little endian, and always runs in that mode.

And now, almost ten years later, there are restrictions in a current Windows version that come from a platform that isn’t supported for more than 5 years and two major versions.

That is because 2GB user address space is not an issue in the marketplace. It is were the consumer version of NT would have lifted the 2GB barrier as it has been on the server version. 2GB is a common problem for large database servers.

Norman

On Sun, 02 Nov 2003 11:25:20 -0600, (jjs) wrote:

In article ,
(Bill Hilton) wrote:

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

From: (jjs)

Either platform – what platforms? Unix and WindoZe?

Windows and Mac … Photoshop 7 wasn’t ported to Unix.

Gosh this gets confusing. Mac OS-X _is_ Unix.

Right and WindowsNT has a POSIX conformity package and may be named UNIX too.

OS-X has a UNIX base plus lots of features that make it a Mac-OS.

Even some "modern mainframes" (ok, that sounds like Microsoft works) run their mainframe OS on a invisible UNIX platform. bUt that doesn’t make them UNIX machines.

And Photoshop is available for exactly two platforms: Win and Mac.

Michael

In article ,
(Xalinai) wrote:

Even some "modern mainframes" (ok, that sounds like Microsoft works) run their mainframe OS on a invisible UNIX platform. bUt that doesn’t make them UNIX machines.

Huh? Like what ‘mainframe’ OSes? I’m afraid the only time-sharing (‘mainframes’) I use is what’s in front of me, Sun and (no kidding) OpenVMS, and one is Unix (not a great Unix) and the VMS is definitely _not_ U*ix. It’s way too good to be U*x.

In article <011120032126478164%>,
Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.
Chris

but not because of the OS on mac side. 10.3 can go full boat.

Our biometrics app on our Dual G5 cluster uses all 8 gigs (16 gigs even on the one test box)

In article ,
Eric Gill wrote:

(Bill Hilton) wrote in
news::

From: Paul J Gans

It is NOT a Photoshop problem. It is a limitation in Windows.
Give unto Adobe that which is Adobe’s. Give the rest to Microsoft.

Does the Mac version have this same limitation?

Yes. Of course, until the advent of OS X, MacOS machines had a limit of
1.5GB. OSX raised this to 2. Why, I have no idea.

OSX for the G5 raises this to at least 8GB, the limit of the hardware,

16 gigs is the limit. Apple just says 8 gigs to cover their butt on the standards issue.

also we use DDR 500 to truly take advantage of the 1GHz FSB

In article ,
(jjs) wrote:

In article <021120031838095647%>, Chris Cox
wrote:

The limitation comes from using 32 bit pointers.
Even BSD is normally limited to 2 Gig per process.

OS X had a 2 Gig/process limit, and that was increased to 4 Gig/process when the G5 shipped — but that was far too late for Photoshop CS to be tested against the new OS (and a change like that will require a LOT of testing — too many new programmers assume that pointers can be casted in and out of signed 32 bit values (sigh)).

You cannot address more than 4 Gig/process without going to pointers with more than 32 bits. And OS X is not yet completely 64 bit clean.

Ah, at long last, the definitive statement! That’s what we need to hear. Okay, I’m happy knowing where it stands, and I look forward to PS CS, and in the future, when Adobe finds all is right, massive RAM capability.

that is in 32bit mode not 64. My guess is that Photoshop uses OS built in function calls for memory allocation etc… so they have to wait on Apple. It may be years before apple gets everything 64bit clean that Adobe needs for such a massive app like photoshop.

lets not forget also that it will be another 6 months to 2 years before the mac side compilers are really generating good 970 code. As an exmple gcc 3.3 is barf and XLC is barely beta etc… (I haven’t used CW in awhile so not sure have it stacks up these days)

Our biometrics app on our Dual G5 cluster uses all 8 gigs (16 gigs even on the one test box)

How. A 32-bit address can only address 4GB. Are you saying you application is a 64-bit and/or segmented application. More to the point, what is the size of a pointer/address type. Or is software involved. For example (lock/unlock)(map/unmap) or some similar concept.

Most modern 32-bit processors, and therefore modern operating systems, can address more than 32-bits of physical memory. In the case of MS they limit this ability to the server OS variants. Even given this a 32-bit process is still limited by 32-bit addressibility. Exactly how a processor translates a 32-bit virtual address into a physical address varies. The IA-32 (Intel) enables this by supporting a mode where 64-bit page tables are used to get the extra physical addressibility. The extra memory lets an OS keep many 32-bit processes in memory without the need for swapping.

Norman

On Tue, 04 Nov 2003 08:16:54 -0600, (jjs) wrote:

In article ,
(Xalinai) wrote:

Even some "modern mainframes" (ok, that sounds like Microsoft works) run their mainframe OS on a invisible UNIX platform. bUt that doesn’t make them UNIX machines.

Huh? Like what ‘mainframe’ OSes? I’m afraid the only time-sharing (‘mainframes’) I use is what’s in front of me, Sun and (no kidding) OpenVMS, and one is Unix (not a great Unix) and the VMS is definitely _not_ U*ix. It’s way too good to be U*x.

Well, the Sun isn’t a mainframe (not even a E10K) and Solaris is already a very fine Unix version (for a proprietary one).

But have a look to Fujitsu or Siemens (BS2000)…

Michael

In article ,
(Xalinai) wrote:

On Tue, 04 Nov 2003 08:16:54 -0600, (jjs) wrote:

Huh? Like what ‘mainframe’ OSes? I’m afraid the only time-sharing (‘mainframes’) I use is what’s in front of me, Sun and (no kidding) OpenVMS, and one is Unix (not a great Unix) and the VMS is definitely _not_ U*ix. It’s way too good to be U*x.

Well, the Sun isn’t a mainframe (not even a E10K) and Solaris is already a very fine Unix version (for a proprietary one).
But have a look to Fujitsu or Siemens (BS2000)…

Just what makes a "mainframe" today? The meaning of the word rather faded from common use a long time ago. Heck, the third fastest Super Computer is a massive multi-cpu cluster of Macintoshes running (ah, running… Linux maybe?) Sorry for being OT. 🙂

Zephead …

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

but not because of the OS on mac side. 10.3 can go full boat.
Our biometrics app on our Dual G5 cluster uses all 8 gigs (16 gigs even on the one test box)

No process on OS X can directly address more than 2GB. The OS won’t allocate it, and there are no APIs that take >32 bit pointers. The only way to use >2GB is to explicitly copy between multiple address spaces or else do buffered file I/O and take advantage of the OS caching the files in RAM.

Russell Williams
not speaking for Adobe Systems

On Thu, 06 Nov 2003 01:49:27 -0600, (jjs) wrote:

In article ,
(Xalinai) wrote:

On Tue, 04 Nov 2003 08:16:54 -0600, (jjs) wrote:

Huh? Like what ‘mainframe’ OSes? I’m afraid the only time-sharing (‘mainframes’) I use is what’s in front of me, Sun and (no kidding) OpenVMS, and one is Unix (not a great Unix) and the VMS is definitely _not_ U*ix. It’s way too good to be U*x.

Well, the Sun isn’t a mainframe (not even a E10K) and Solaris is already a very fine Unix version (for a proprietary one).
But have a look to Fujitsu or Siemens (BS2000)…

Just what makes a "mainframe" today? The meaning of the word rather faded from common use a long time ago. Heck, the third fastest Super Computer is a massive multi-cpu cluster of Macintoshes running (ah, running… Linux maybe?) Sorry for being OT. 🙂

I use the word "Mainframe" for a legacy type computer, one of the last dinosaurs from times when harddisks measured 14".
Even if hardware technology has changed, their operating systems still exist and some applications survived more than twenty years.

To avoid the hassle of creating new hardware, emulators were written, so that the emulated dinosaur runs faster than the original one.

Some people in my environment tend to use "mainframe" as a derogative….

Michael

Russell Williams wrote:

Zephead …

Chris Cox wrote:

Yes, that is correct – that is a limit of both Photoshop and your OS. Photoshop can only use 2 Gig of RAM, on either platform.

but not because of the OS on mac side. 10.3 can go full boat.
Our biometrics app on our Dual G5 cluster uses all 8 gigs (16 gigs even on the one test box)

No process on OS X can directly address more than 2GB. The OS won’t allocate it, and there are no APIs that take >32 bit pointers. The only way to use >2GB is to explicitly copy between multiple address spaces or else do buffered file I/O and take advantage of the OS caching the files in RAM.

Russell Williams
not speaking for Adobe Systems

Well, that’s two different things. A 32 bit pointer can address 4 GB. The OS not allowing more than a 31 bit pointer is something else.

But in any case there are hardware schemes to allow 32 bit pointers to address any sized memory via hardware page allocation, etc. Such schemes were very common back in the Good Old Days ™.

—- Paul J. Gans