NOTE: Metro Atlanta has 21 school systems (16 County and 5 City school systems). There are many more private schools in the area. Steve Ostenson has accumulated the public school data provided by the Georgia Department of Education and ranked the public schools based on their test scores for each grade (K-8) and the high schools by their SAT scores. Take a look at the Metro Atlanta public school rankings to see how your school ranks.
Keep in mind that you shouldn't base your decision on a school solely on its test scores. There are many more criteria that should be weighed before choosing the school district to live in.