Question Can my cpu reach 5ghz with my motherboard

With CPUs it's a lottery, sometimes it's not even the motherboard or the cooling. Obviously the main thing is the cooling but a mix of proper cooling, motherboard and a good cpu will get you good overclocks.

 
Sounds like you have reached your CPUs Max overclock. I had an i7 7700k that couldn't go over 4.8ghz even though it had more thermal headroom. You can go into your bios and try to adjust your overclock manually, in my experience this has always gained me better clock speeds and lower temps. But as it's been said before it's the silicon lottery.
 
First Your Motherboard supports overclocking. You can reach 5 GHz too.

Steps how to reach.
  1. First Unlock your multipliers from Bios.
  2. increase your Core Voltage. To max 1.35-1.38 volts per Core.
  3. Use a good cooler to stay below 50° C.
To maintain your CPU speed at 5 GHz.
  1. Use at least 650 watt of power supply. With max power on 12volt Rail.
  2. Do not tweak with FSB. Which is 100MHz use only Multipliers to reach 5 GHz. Otherwise you can face Crashes.
  3. Last don't used your CPU for long at 5GHz. It can damage your Motherboard or CPU.

Wolla done. .