A few days ago I bought my new S2417DG monitor and it has been working fine but I cannot overclock my monitor. I've tried plenty of stuff and I do have my monitor and graphics card latest drivers. Every time I try to overclock the monitor on the On Screen Display (OSD) the monitor, after enabling the overclock and choosing the 165Hz option, asks me if i would like to reboot so that the overclock could be applied. I select "yes", then the monitor restarts but nothing changes. It is still on 144Hz after the reboot and there is no option on the windows settings to let me go further than just 144Hz. I would really appreciate some help on this issue, thanks in advance.
Other stuff that may be important to know is that I'm using windows 10 and I have an AMD graphics card at the moment (R9 390), so I'm not using the G-sync feature for now.
Unfortunately, you are using a non-validated AMD video card. So there will be issues. Our advice, get an Nvidia video card.
We tried to prepare buyers in our sales and other documentation about the Nvidia video card requirement.
Let's start with the Dell S2417DG sales site. Zero references to AMD, but four to Nvidia.
In this article, How to Use and Troubleshoot the Dell S2417DG Gaming Monitor, it states;
"Nvidia G-Sync-enabled and Nvidia 3D Vision Ready monitor, with a extremely high refresh rate of 144Hz (165Hz with overclock) and a rapid response time of 1 ms."
Later it does mention AMD in a negative light;
"The Dell S2417DG monitor may not be able to display at an optimal resolution when connected to a PC with an AMD graphics/video card. To resolve this issue, disconnect the display cable (HDMI or DisplayPort cable) and reconnect the cable to the monitor."
The online User's Guide also makes no mention of AMD. It only references 165Hz with Nvidia.