iMac hardware upgrade

Does this machine also allow me to physically upgrade the graphics card?

No. Starting with the 2012 iMacs, the graphics hardware change from socketed to soldered to the logic board. It cannot be changed.

Beyond that, we would be doing your a disservice if we offered further upgrade options without first asking for hard performance data. There could be something else slowing your workflow. Fortunately there is a safe, secure way to do that. 

We can quickly and within the confines of these forums help you determine what issues are at play if you use EtreCheck, available free from the Mac App Store here:

https://itunes.apple.com/us/app/etrecheck/id1423715984?mt=12

We can see hard data about drive performance, software issues, and RAM usage. Etrecheck is the development of a long-serving and trusted contributor here expressly for displaying information in these forums to help us help you. It will not reveal any personal or secure information.

Run it, select “Report" from the left-hand pane (scroll down to the bottom of that pane to find):

When its report displays, click the "Share Report" icon from EtreCheck’s toolbar and then "Copy report” from the resulting dropdown.

⚠️ Please DO NOT highlight the text in the report before using Etrecheck’s “Copy report” command—that will garble the formatting and make the report slower and harder to evaluate.

NOTE: Changes in late 2018 to the forum software require you use the “Additional Text" icon (see example below) to embed the report into a post:

Paste the report into the resulting “Additional Text” window:

More memory will help - Photoshop and Lightroom are memory hogs. Your computer has 4 memory slots each of which can be configured with a 16GB card for a max of 64GB of RAM. The last time I used those two programs I was running with 32GB at work and 16GB at home. I noticed a distinct difference between the two and the work computer was actually a slower computer.