El Paso, Texas is 713 times larger than Round Rock, Texas.
Area: 1 km2 calculated
Round Rock is a city in the state of Texas within the Greater Austin, Texas metropolitan area and Williamson County. The 2013 census estimate places the population at 109,821. Wikipedia
Area: 701 km2 calculated
El Paso is the county seat of El Paso County, Texas, United States, and lies in far West Texas. As of July 1, 2013, the population estimate from the U.S. Census was 674,433, making it the 19th most populous city in the United States. Its U.S. Wikipedia