Recently got a new gpu (rtx 2070) and it isn't at it's full potential, I tried uninstalling drivers from my old gpu (rx 480) via device manager and it sait it had uninstalled the drivers and that it worked but I'm not sure if it did as I don't have amd catalyst manager. The other potential issue could be my cpu, it's an i5 6600k at 3.6ghz.
Download Intel XTU and select the stress test. Run the test for 5 minutes (it will take less if you have a cooling problem) and watch the temperature. If it gets to hot the CPU will throttle and the graphic will turn yellow. If it turns yellow on stock settings, then something is wrong with your cooler. Either it is not seated on the IHS properly or you have used too little/too much/or no thermal paste.