A few things to check:
• Have you enabled XMP (or DOCP as it might be called) in the BIOS, then set the automatic specs to 3200MHz if applicable? If not, do that now, as this will get the RAM running at full speed. It should be with other overclocking settings.
• Is the RAM in slot 2 and 4? If not, change it, so that it goes empty, RAM, empty, RAM. This effectively doubles the bandwidth of data to the CPU.
• Are the newest drivers for the RX 470 installed? If not, uninstall the ones you have, then get the newest ones available from AMD's website. Don't use the ones that came with the disc, if you got one, as these are outdated.
• Is the monitor plugged into the graphics card or motherboard. It should always be plugged into the graphics card when one is available.