Connecting my iMac 27 (2017) to a 144 hz monitor

Hi, I have a 27 inch Imac (2017) Radeon pro 575 GPU, and I try to connect my Benq XL2411 monitor to have a refresh rate of 144hz. I use the DVI-Dual cable from the monitor to an adapter DVI-Dual (29 pin) to USB-C . The connection is working, but I can’t get 144hz or even 120hz to work properly, using either OS, or windows 10 via dualboot.

On the Mac side, I can get 120 hz, but the monitor is showing an error message (wrong connector). The error message stay there in the corner of the screen, even in game.

On the Windows side, in the display menu, the « adapter display properties » won’t show other refresh rate that 60 hz.

I don’t know what to do. I could even be fine with 120 hz, but even that, I can’t get is to work properly.

Thanks for any help,

Maxime