Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

MacPro w/10 GB RAM - Photoshop only "sees" 3072 MB? Huh?

DHart

DHart

macrumors 6502
Original poster
Jan 17, 2008
398
12
Well, I just installed 8 GB of additional RAM in my new Mac Pro, bringing my total to 10 GB. The System Profiler shows all 10 GB being there... but when I go into Photoshop/Preferences/Performance to up the usage of RAM, it only shows 3072 MB of "Available RAM".

Shouldn't Photoshop see at least 7000 or 8000 MB of available RAM? I did quit and restart Photoshop and it made no difference, still just says "3072 MB of available RAM".... can anyone help me figure this out?

I love this MacPro! Thank you.
 
No.... oh no. Windows is not allowed anywhere near my place....
 
Unfortunately, the 3GB memory limitation is that of Adobe.

Why don't you google:
adobe 3gb memory limitation
 
Consultant... thank you. For a few minutes I was wondering WHY I went and bought 8 more GB of RAM for Photoshop, not knowing the limitation of 3 GB.

I did as you suggested, found the following, and implemented it! Awesome.

Work around Photoshop's 3GB RAM limit
Fri, Jul 18 2008 at 7:30AM PDT • Submitted by Anonymous

With RAM prices dropping so fast, it seems a shame that I can't really use more than 3GB of memory for Photoshop. As a 32 bit application, Photoshop CS3 can only "use" 4GB of real memory -- a 1GB chunk for the application, leaving a potential 3GB of real RAM available for Photoshop to use for my images. For anyone with 8GB or more of memory, here's an old concept that tricks Photoshop into using as much memory as you want.

Remember RAM disks from OS9? The feature is available in the command line in OS X. By creating a RAM disk, and having Photoshop use that as the first scratch disk, you'll speed up Photoshop as long as you have enough real memory to do it. For my test, I allocated 3GB to Photoshop in its prefernces (real memory usage), and then created a 2GB RAM disk.

The Terminal command to create a 2GB drive is:
hdid -nomount ram://4194304
The number is the number of 512 byte blocks in your RAM disk. The example above creates a 2GB disk, so a 4GB drive would be 2x that number, and a 1GB drive would be half that number, and so on. Once the disk is created, format it with Disk Utility. Then configure Photoshop to use the RAM disk as your first scratch disk. As soon as CS3 hits the 3GB memory barrier, it starts using the RAM disk as "memory" first. Remember, it will be "swapping" memory pages in and out of the 3GB memory set, but this is still better than swapping to and from a hard drive.

I created a 4.5GB file in Photoshop, and was pleased to see almost no disk activity on my real drive, but my RAM drive was full during my test.

Note: This really only helps someone with 8GB or more of memory running CS3 a lot. For example, if you had 16GB of memory, you could create an 8GB RAM disk, and then allocate 3GB in CS3, effectively having Photoshop "use" 11GB of real memory before hitting the disk. Also note that RAM disks are not quite as fast as regular memory access native to an application, but they are much faster than having CS3 swap to your hard drive.

While it takes some steps to get this configured, I thought there might be some people out there interested in improving how CS3 uses real memory, since there is no 64-bit version yet.
 
Consultant said:
Unfortunately, the 3GB memory limitation is that of Adobe.

Why don't you google:
adobe 3gb memory limitation
Click to expand...

The trouble is.... 99% of the users on those board don't know what the search thing does, and your asking them to use Google?

Dude, they even write Dummy books for Blogger, it's just a matter of time for a Google search one... no wait, O'reilly releases one called "Google hacks" - possibly too advance for kid here, huh? :D
 
UltraNEO*.... Google is as easy as it gets... what are you talking about?
 
DHart said:
UltraNEO*.... Google is as easy as it gets... what are you talking about?
Click to expand...

trying to make a fool of themselves.


back to original post.

there arent many applications available atm to run more than 4 gigs of combined process, but 10gigs is a good amount to do everything i can possibly think of.

i mean i only run 1 gig and can run garageband, photoshop, aim, msn, firefox, safari, and itunes all at once.

so 10 gigs = god like, multiprocess usage.
 
PS3 on 10.5 or later will see more than 3 GB RAM

No need for a RAM Disk with OS 10.5 or later, the OS automatically spills Photoshop's needs to available ram before going to the scratch disk (hard drive). If you have 6 or more GB of RAM, set PS Performance to 100% (3 GB) and the OS will automatically let PS use the extra RAM beyond 3 GB.
 
From Adobe:
Allocating Memory above 2 GB with 64-bit Processors
When you run Photoshop CS3 on a 64-bit operating system, such as Mac OS X v10.4 and later, Photoshop can access up to 8 GB of RAM. You can see the actual amount of RAM Photoshop can use in the Let Photoshop Use number when you set the Let Photoshop Use slider in the Performance preference to 100%. The RAM above the 100% used by Photoshop, which is from approximately 3 GB to 3.7 GB, can be used directly by Photoshop plug-ins (some plug-ins need large chunks of contiguous RAM), filters, and actions. If you have more than 4 GB (to 8 GB), the RAM above 4 GB is used by the operating system as a cache for the Photoshop scratch disk data. Data that previously was written directly to the hard disk by Photoshop is now cached in this high RAM before being written to the hard disk by the operating system. If you are working with files large enough to take advantage of these extra 2 GB of RAM, the RAM cache can increase performance of Photoshop.
The default RAM allocation setting in Photoshop CS3 is 70%. These settings should be optimal for most users. To get the ideal RAM allocation setting for your system, change the RAM allocation in 5% increments and watch the performance of Photoshop in the Activity Monitor. You must quit and restart Photoshop after each change to see the change take effect.
The available RAM shown in the Performance preferences has already deducted an amount that is reserved for the operating system from the total RAM in your computer. You shouldn't set the percentage of RAM to be used by Photoshop to 100% (unless you are using more than 2G of RAM) because other applications which run at the same time as Photoshop (for example, Adobe Bridge CS3) need a share of the available RAM. Some applications use more RAM than you might expect. For example, web browsers can use 20-30 MB of RAM, and music players can use 20-50 MB of RAM. Watch the Activity Monitor to view the RAM allocations on your computer.
Watch your efficiency indicator while you work in Photoshop to determine the amount of RAM you'll need to keep your images in RAM. The efficiency indicator is available from the pop-up menu on the status bar of your image or from the Palette Options on the Info Palette pop-up menu. When the efficiency indicator goes below 95-100%, you are using the scratch disk. If the efficiency is around 60%, you'll see a large performance increase by changing your RAM allocation or adding RAM.

If you do have 4 GB or more of RAM, you should set the percentage of RAM used by PS to 100%.
 
Adobe CS4 is 64-bit... only on Windows. If you install Vista x64 under Boot Camp and Photoshop CS4 for Windows, you can use all 10 GB in Photoshop.
 
WonderSausage said:
Adobe CS4 is 64-bit... only on Windows. If you install Vista x64 under Boot Camp and Photoshop CS4 for Windows, you can use all 10 GB in Photoshop.
Click to expand...

You don't have to do that to make use of extra RAM.

Through the design of OS 10.5, Photoshop will use the extra RAM beyond 3 GB in a Mac, under OS 10.5, as a very quick scratch disk until the available RAM is used up and only then go to the hard disk for scratch purposes if it needs to. So if you have, say, 10 GB of RAM in your Mac (as I do), set your PS Prefs to use 100% of the RAM (which will show a little over 3 GB) and OS 10.5 will use any extra RAM beyond 3 GB, as needed, as scratch for Photoshop. Thus, OS 10.5 enables Photoshop to use the extra RAM beyond 3 GB, even though PS is 32-bit on the Mac.
 
DHart...

I don't think what your reading is correct!
Why don't you give references to the information your quoting? It'll give you more creditability, right now I'm only smelling BS and it stinks. Unless your some mathematical genius and you've found out a why to bend/warp and distort the physics of how many bytes of information a thirty-two bit application can support, your just talking from your ass.

In the attachment below, you'll see I'm actually running a system that's sixty-four bit and loaded with ten gigabytes of ram. I've attempted to allocated 100% memory to the application.. and if you look carefully, you see it's only allowing 3072MB (100%).
 

Attachments

  • photoshop.jpg
    photoshop.jpg
    469.1 KB · Views: 310
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back