Video card

MacTracker shows the options for the iMac (27-inch, Late 2012) as

• NVIDIA GeForce GTX 660M with 512 MB of VRAM
• NVIDIA GeForce GTX 675MX with 1 GB of VRAM
• NVIDIA GeForce GTX 680MX with 2 GB of VRAM

The users posting to this MacRumors thread seemed to believe (read the thread all the way to the end) that the GPU was soldered to the motherboard.

Apple says that iMacs introduced in 2012 or later support Metal and Metal2 when running Mac OS X El Capitan or later. It does not appear that iMacs introduced in 2012 support Metal3.

Support for Metal on Mac, iPad, and iPhone - Apple Support

[Link Edited by Moderator]

Unlikely. Time for a newer Mac if you want better performance. Plus, you can't upgrade beyond Catalina 10.15.7.

Like dialabrain say, not likely, but which graphic card does it have?

Adobe – Photoshop GPU FAQ

https://helpx.adobe.com/photoshop/kb/photoshop-cc-gpu-card-faq.html