Hi S.name,
I'm Amr, an independent advisor.
To check the DPI of your SteelSeries Rival 3 mouse, you can use the SteelSeries Engine software
You can download the software from the SteelSeries website and install it on your computer.
Once installed, open the software and select your mouse from the list of devices. You can then adjust the DPI settings and see the current DPI value of your mouse.
I hope this is helpful. If you require any additional assistance, don't hesitate to respond to this.
Best Regard
Amr