Help with 2010 21.5" iMac MDP to HDMI QHD resolution

[zodpunk]

Hello! I've got a 4K TV that I'm using as an external monitor for my 2010 21.5" iMac. Currently, I've got a MDP to HDMI adapter, but I know that has a 1080p max resolution. I know that this model iMac can push a 2560 x 1440 QHD resolution through a dual-link DVI adapter. However, I only have HDMI ports on the TV. The TV can support QHD.

I have tried the Macally Mini DisplayPort 1.2a to HDMI adapter (MDHDMI4K). But it doesn't support 2560 x 1440.

I have searched online and found some dual-link DVI to HDMI adapters, but from what I've seen many complain that most of the adapters still only provide 1080p. Has anyone been able to successfully use a monitor or TV with the QHD resolution on this model or similar iMac?

 

[zodpunk]

Update: I have tried the Plugable brand: Active Mini DisplayPort to HDMI 2.0 Adapter and the Cable Matters brand: Active Mini DisplayPort to HDMI Adapter. This has allowed me to get even higher resolution than I hoped! I'm currently displaying 3840x2160 on a 43" TV... it is glorious! The only drawback is that I can only get 30Hz, but I can't complain for what I did get! After all 1080p on a 43" felt like I was looking at a minecraft version of my desktop screen.

I've attached the 'Displays' screenshot from my "About This Mac" as well as the actual results.