Graphic design: extra RAM?

Open Activity Monitor and go to the System Memory* tab and look for Page Outs and Swap used and report back.

Using Activity Monitor to show you CPU and RAM usage​

* Mac OS X: Reading system memory usage in Activity Monitor​

An additional 8 GB RAM via two 4 GB modules costs less than 50 USD nowadays via Newegg and similar sites, that sell 1333 MHz 204-pin DDR3 SO-DIMM RAM modules.
Your iMac can take up to 32 GB RAM via four 8 GB modules, which costs around 200 USD, thus you can have 12 GB for 50 USD, 16 GB for 100 USD or 32 GB for 200 USD.

 

With only 4gb of RAM Photoshop might be using its scratch disk, this will make everything run slower. I wouldn't consider running PS on less than 8gb. RAM is pretty cheap and the extra won't make it run any worse.

 

More RAM can help, you should have 2 slots free so maybe another 4Gb or 8Gb, which is be pretty cheap now.

Ramcity has 2x 2Gb from $62, 2x 4Gb from $78

http://www.ramcity.com.au/system/71472.htm

Have you considered upgrading CS5 to CS6?

ETA - I have just 4Gb in my older G5 PM running Leopard and CS3. It runs just fine most of the time, a little slow on some tasked but this PowerMac is 7 years old.

 

The page outs and used swap mean, that you need at least 1 additional 1 GB RAM with your current usage.
And the extra RAM will make the applications react faster.

What is RAM? - measured again in MB and GB

 

As I said I'm still using CS3, might get CS6 with my new iMac, if I can afford it.

FYI checked my page outs and swap used, both are on zero. Good thing since my G5 is at it's max RAM right now.

 

The graphics-related lag you are experiencing might not be resolved by increasing your RAM. I experienced lag and slowness/stuttering working in CS5 and FCPx and I believe my graphics card upgrade is what helped me. See my below Before (lag) & After (everything smooth as butter)
2011 27" iMac

before:
6770m 512mb
16gb Ram
i5 2.7ghz

after:
6970m 2gb
32gb Ram
i7 3.5ghz

It definitely wasn't the RAM that helped in my case, cpu upgrade may have helped, but I firmly believe it was the graphics card swap that did the trick.

 

That is very interesting I always thought that graphics card was more gaming purpose to drive things to display at certain frame rate. Why should CS5 be affected with graphic card ?

 

To be honest, even scrolling web pages was choppy before the upgrade, now completely smooth. I believe any graphical display on the screen is controlled by the graphics card -- the higher the pixel & color density, the more powerful chip & more vram required. Correct me if I'm wrong but this is my understanding of it.

 

To be honest I'd be very skeptical if that is realted to video card. I see you moved from i5 to i7 as well as you doubled your ram from 16gb to 32 gb. Simple browsing should not have anything to do with your upgrade as what you had was more than capable of handling your requirement. There is definetly something else going on there.

 

What else do you think was the problem? I had the same OS X Lion (still running this). Btw, I've always kept my display at the highest resolution 2560x1440.
When I was experiencing graphics-related lag I had 16gb RAM which was more than enough; most would agree the Core i5 2.7ghz is fast enough. I believe the graphics card was the weak link in my graphics-related performance. At my resolution, on a 27" screen, it didn't surprise me I had performance issues scrolling, and while image & video editing. After the upgrade everything is fast and smooth. The way I thought it should've been when I first purchased the iMac.

 

Get an external hardrive (Thunderbolt/ Firewire) and use it as a scratch disk for photoshop. This will help a bit, especially when saving large files or using photoshop autosave.

 

why not buy an extra 4gb x 2 memory and add on top of your existing 4 GB.
imac has 4 slot. 4gb memory module is quite cheap these days.