The President did not order raises. He issued an EO reversing the pay freeze that took effect back in January 2011 for all federal civilian employees. The .5 percent raise would be less than the normal automatic raises that are based on cost-of-living, among other factors as determined by each Agency.
Ms. Tree described the process for congressional pay in a previous post very well.
http://www.usatoday....freeze/1799011/
"President Obama and Congress agreed in the fall to maintain the freeze that began in January 2011 through the end of the current continuing resolution. Obama recommended a 0.5 percent pay increase next year for feds when Congress passes a budget. It remains unclear when or if that will happen.
"Lawmakers passed the $1.047 trillion continuing resolution in September. It funds the government through March 27. The stopgap spending measure ensured feds would not see a salary bump until April at the earliest."