iMac 27" mid-2011: 32GB RAM?

When I got my 27" iMac around mid/late-2011, I took out the stock 4GB RAM, and installed 16GB. I'm finding it lagging a little now, when performing multiple simultaneous tasks in Adobe Lightroom/Premiere/Photoshop. I know that when my machine was new, Apple would only configure it up to 16GB RAM, but I would love to know if it would be physically capable of supporting 32GB RAM.

Here's a screencap of my system specs. Does anyone have any experience similar to this?

Yes, your 27" iMac around mid/late-2011 can use 32 GB RAM as maximum, see:
Apple iMac Specs (All iMac Tech Specs) @ EveryMac.com

I have the 2.7GHz 27" model with 20 GB Ram.

But before you go stuffing it with more memory, I'd suggest you check and do some maintenance but especially keep a watch with Activity Monitor to see what you iMac is up to a doing with the RAM already installed. And adding more memory isn't always the magic bullet to gain more speed.

I would definitely do what "pm-r" suggests. Do some maintenance first. 16gig of ram is a pretty good amount…and adding more may not solve anything.

Check on:

- free HD space.
- run the maintenance app "Onyx"

* Nick

Thanks for the tip, guys!

I'm going to keep a close eye on Activity Monitor. My RAM is currently about 75% taxed, with one process I never really need chewing into 2.98GB. Glad I now know about this tool.

It sure sounds like you can sure get rid of that resource hog, especially if it's not even needed!!