The Relief valve pressure is more or less than system pressure.

logic .....it must open at pressure minimum1.5 any system pressure 

A Relief Valve Set Pressure shall always be greater (1.2 to 1.5 times) than the normal operating Fluid Line Pressure. Relief Valve is used to Vent the Fluid in case of excess Pressure & It should be normally closed under normal operating process conditions

Relief Valve pressure is less than the system pressure.

System can generate more than the set pressure but to optimize the system functioning in the specified  mode/level, there by to protect and make smooth functioning.

I would first narratte the question correctly as

"The Relief valve set pressure is more or less than system pressure"

If this is the question the answer is " Yes, Relief valve set pressure is greater than the system pressure (operating pressure).

Set pressure is the pressure (greater than operating pressure) at which the safety relief valve strats to open.

relief valves are less than the system pressure, thats why it called relief means to bring "ease" at the system pressure.

A relief system is an emergency system for discharging gas during abnormal conditions, by manual or controlled means or by an automatic pressure relief valve from a pressurized vessel or piping system, to the atmosphere to relieve pressures in excess of the maximum allowable working pressure (MAWP)

function of relief valve is to release the pressure when it exceeds a level. so obviously it should be equal or less than the system. So that it can indicate before reaching the system.