If it ain't broke... tweak it

Optimising your PC or MAC can be tricky enough but designing it to specifically suit Photoshop and your image workflow presents additional challenges. If like me you've already got a PC or MAC then you probably don't want to spend any more money on an upgrade which may or may not work. The best you can do is tweak the system you have now to get more out of it. 

I've started with a list of questions which normally arise when trying to increase the speed of any software followed by a search on Adobe.com for technical notes (TechNotes) and e-mailed the knowledgeable people at National Association of Photoshop Professionals (NAPP) for their take on Photoshop memory management.

My initial questions are below:

• Does Photoshop 'manage' memory or should I install a 3rd party memory manager?
• What graphics card should I install and will Photoshop use all, some or none of the memory onboard the card?
• How big a scratch disk do I need and will I run the risk of wearing out that drive by constantly reading/writing to it?
• How much RAM should I have?
• How much Virtual Memory should I allocate to programs over background tasks?
• Can I test the efficiency of Photoshop after I make system changes?
• Are technical specifications for Photoshop memory usage available?
• What features should I enable/disable in Photoshop to speed things up?

 My searches on Adobe.com led me to the following articles:

Optimize performance of Photoshop CS5 and CS4 on Windows 7, Vista, and XP
Optimize performance in Photoshop CS5 and CS4 on Mac OS
List of tested graphics display cards for Photoshop CS4
List of tested video cards for Photoshop CS5
GPU and OpenGL Support in Photoshop CS5 and CS4
Photoshop CS5 64-bit benchmarks

The first thing to do is work out how to benchmark your system, aside from the obvious changes of seeing filters apply quicker and images load faster I want to be able to definitively say whether a change has made a difference.
John Nack in his blog mentions a couple of benchmarking tools but if you don't want to go down that route the easiest test is to choose a typical file you would work with (typical being the normal size of image you would shoot, download and edit) then choose a filter or range of edits to perform on your image. For consistency you can add these functions to an action (Sample actions used for benchmarking are here) or simply repeat them manually. Choose a complex filter that will tax your machine sufficiently to see a real difference. 

In Photoshop open the Window>Info (F8) panel
Click the panel menu then Panel Options...
Tick Scratch Sizes, Efficiency and Timing
Click OK
You can now see these settings in the Info Panel. When you perform a function in Photoshop, the time taken (in seconds), efficiency of memory use and scratch disk space available will be shown. Some filters such as Unsharp Mask, Gaussian Blur, etc. use only processing power so if these run slowly you need a faster processor or to adjust your PC settings rather than your Photoshop settings.
Working with large images, multiple images or files with multiple layers will test your memory and the speed of your scratch disks.

For my own benchmarking I'm using the Photoshop Speed Test
Following the instructions I have set my History States, Cache Levels, Memory Usage and Processor Usage according to the Read Me file. To access these settings go to Edit>Preferences>Performance

The Read Me file says that no other program should be running when benchmarking but I will be leaving my background programs running such as Skype and anti-virus as these are the minimum programs which are ALWAYS running whenever I am using Photoshop. To close these would be to create a false benchmark for my personal system.

Test 1: Default Benchmark Settings
Windows XP Pro SP3 (32-bit)
Intel Xeon CPU 3.00Ghz
2.00 GB RAM
For the stopwatch I used the stopwatch feature on my iPhone.
Test 1: 1 min 43 seconds - DEFAULT BENCHMARK SETTING

From this point onward I will make a change to the settings or system and rerun the test from a reboot. A reboot clears the RAM and temporary files so to keep things consistent I will have to reboot after each system change. 

Test 2: Run FreeRAM XP Pro
Normally I run FreeRAM XP Pro to manage memory while using lots of programs. On a busy day I can have around 10 programs running with up to 25 tabs open within FireFox and occasionally Internet Explorer at the same time. FreeRAM XP Pro manages this heavy memory usage very well but does warn that it can slow certain programs down. I rebooted with FreeRAM XP Pro on default settings, launch at Windows startup and AutoFree: Automatically optimize to balance speed and memory.
Test 2: 3 mins 21 seconds - FAIL

Test 3: Change Windows System Properties
Right-click 'My Computer', left-click Properties
Take a note of the RAM for your computer. (e.g. 2.00 GB RAM)
Under the Advanced tab, under Performance, click Settings
In the Performance Options dialog box click Advanced tab
Check Processor Scheduling is set to Programs
Check Memory Usage is set to Programs
Under Virtual Memory click Change
Here your system is most likely set to System Managed Size
If your computer is old or very well used it's quite common for RAM chips to fail. The whole RAM stick may not have failed but individual failed chips will contribute to slow performance and system freezes. If you know your machine should have more RAM try swapping the RAM sticks with new ones to boost performance.
The Paging File (Virtual Memory) is physical hard drive space used for processing information when there is insufficient RAM. RAM and the Page File can only be accessed independently, never at the same time so there is a delay between accessing the RAM and accessing the Page File. We can boost performance here in a number of ways. The first is to dedicate a hard drive to the Page File. Choose a fast hard drive that is not accessed very often. My system is by default set to C:\ drive with a custom Page File size of Intial Size: 2046MB and Maximum Size: 4092MB.
I clicked on D:\ then chose System managed size
Now drives C and D can be used for Page File access.
The more drives you can spread the Page File across the better your performance will be, but do not spread the Page File across partitions or Fault Tolerant drives as this will slow performance.
Ideally you want to put as much RAM into your machine as possible and lower the Page File access as much as possible. Turning off the Page File will cause your system to crash occasionally as it is used for other things as well as memory management though.
Detailed information on profiling your personal system can be found by clicking here.
For myself I have added drive D:\ and set it to System managed size. The system will require a reboot after you change these settings.
Test 3: 1 min 43 seconds - NO CHANGE
While there was no change in results for this test, the additional memory will definitely come in handy when working with larger and multiple files. It's also worth noting that defragmenting your hard drive will speed up Page File access but only if you defrag the Page File - this DOES NOT  happen when running a normal defragmentation. For details on how to defrag the Page File click here.

Test 4: Bigger Tiles
Bigger tiles is a plug-in that ships with CS4 that will improve the redraw time of your images on screen. It requires more than 1GB of RAM to be installed and can be good news if you work with large or complex images. As a Picture Editor this includes me but the majority of my work is minor fixes to multiple images (50-100 per day) so this plug-in will actually slow my system down. Installation instructions can be found here. For the purposes of the test though I will install it to see the results.
Test 4: 1 min 28 seconds - 15 SECONDS FASTER

Additional tests from Adobe relate to working with specific file types, how you preview and work with images and hardware. These are all useful settings and it's worth tweaking the options that relate to your workflow and type of image production. The primary tests above are the first tests I can perform without upgrading my hardware.
With an OpenGL graphics card already running and turned on in Photoshop (Edit>Preferences>Performance) I am utilising the memory on the graphics card. Other options such as defragging your hard drives and running system cleanup are also explained on the Adobe page but I perform these regularly so I won't see an increase in speed from running these now. Lots more information can be found on tuning your MAC on this page as well including details of the Bigger Tiles plugin and DisableScratchCompress which will significantly increase your Photoshop performance on a MAC.

• In conclusion additional RAM will be the first upgrade I make to my PC to bring it up to 4GB unless I move to Windows 7, 64-bit in which case the amount of RAM available is limited by your motherboard RAM chip spaces and your budget.
• My additional memory manager slows Photoshop down substantially.
• Changing the Windows Page File settings improve memory usage for large files and multiple files or when working with lots of programs open.
• The Bigger Tiles plugin speeds up redraw times substantially but making lots of smaller changes to multiple images may be slower.