Sony's PS4 remains in the console lead, though hardware sales are twice as high last month as they were one year ago. Courtesy/Sony

Gaming console sales are booming, but the games themselves? Not so much. Sales of eighth-generation gaming consoles PlayStation 4 and Xbox One have doubled from July of last year when Microsoft and Sony’s previous generation of devices, Xbox 360 and PlayStation 3, were on the market.

In July, U.S consumers spent $514.3 million on new gaming hardware, software and accessories, according to The NPD Group, up 16 percent from last year. All of that gain came from console sales, which were up 100 percent to 198.8 million; sales of the games themselves were down 15 percent to $178.2 million.

July is typically a quiet month for software sales. “Similar to the pattern seen in seven out of the last nine months, strong growth in hardware sales offset declines in software sales in July 2014 while accessory sales had modest growth, leading to an increase of 16 percent in overall new physical video game sales compared to July 2013,” NPD Group’s director and gaming analyst Liam Gallagher said.

Software sales dropped last month, with zombie horror game “The Last of Us” leading in sales. A remastered version of the title hit shelves on July 29, so it’s likely we’ll see the game sell even more units during August. The second highest-selling video game was sandbox indie game “Minecraft.”

Meanwhile, Sony (NYSE:SNE) remains in the hardware lead with a staggering 10 million units sold. During video game fair Gamescom in Germany this week, the Japanese multimedia conglomerate announced it reached the impressive milestone nine months after the console's Nov. 15 launch.

The Xbox One, which launched last year on Nov. 22, continues to trail behind Sony, even though Microsoft released a cheaper version of the device without the Kinect on June 9. Microsoft Corporate Vice President Phil Harrison hopes this sales figure will change when the Xbox One launches in 29 countries this September.