iMac (21.5-inch, Mid 2011) OS Catalina

Very good. In iMacs, those listed as sub-model "Late 2012" and newer have Metal-capable graphics hardware and can run Mojave and later.

"About this Mac.." will show that sub-model with the date:

Note that 21.5-inch iMacs made from Late 2012 do not allow users to add RAM, so find one with 16GB RAM to avoid future disappointment. 27-inch models still allow users to add RAM so it is not an issue with the larger iMacs. The 27-inch iMacs also are more likely to have a faster hard drive.

If you are in N. America, remember to check Apple's refurbished web page. We get all our Macs and iPad from the refurb store and all have been excellent performers.

Refurbished Mac - Apple

Only iMacs that have Metal which is GPU functionality will run Catalina. Those Mac became available in 2012. For more information on Metal please click https://developer.apple.com/metal/ .

One last thing, no your 2011 cannot be upgraded and no there is no work around.

Rather than download a third-part utility, you can use a tool already on your Mac to check for Metal support. Do "About this Mac..." from your Apple menu and, in the resulting window, click "System Report..."

This launches the utility System Information. In the left-hand contents pane, select "Graphics/Displays." The main pane changes to this:

If it looks like that you have Metal support.

However, others have already answered you question. Other than a few Mac Pros (expensive workstation desktop Macs), NO Mac made before mid-2012 has Metal support. So the answer is still "can't" for your 2011 model.

Actually, it's easy, once you know how. What you have to do (and this is what worked for me) was finding a copy of OpenGLExtensionsViewer (it's an app), and it'll tell you various things, including if your video/graphics card is Metal capable

and thus able to be upgraded to Mojave, maybe Catalina. For the record, you can probably update your iMac to El Capitan for sure.....Mojave ? maybe --- there's a slim chance, officially, (you'd have to check the requirements)

as for Catalina---forget it. From what I've read here, it's best described as the update from heck.

john b

Ann T Mora,

You can locate Apple refurbished Mac at www.apple.com and then scroll to the bottom of the page. You will find them by clicking the "Refurbished and Clearance" link. If you do not find what you want, check very often as inventory turns over VERY fast. These machines have no down side, they are identical to new, have the same warranty as new, are eligible for AppleCare, can save hundreds of dollars. My last several Macs have come from the Refurbished store and I have been satisfied with every one.

No. Your iMac does not support Catalina.