Some of the world's fastest Internet speeds let you download an HD movie within 7 seconds. But next month, Atlanta will get access to Internet service from Comcast that will cut that time in half.

Comcast announced on Thursday that it will soon begin offering a service capable of delivering Internet speeds of up to 2 gigabits per second — that's twice as fast as Google Fiber's top speeds and 200 times what the average U.S. household currently gets. And, the company claims, it will soon be available to 1.5 million Atlanta residents.

The service, which is called Gigabit Pro, is a none-too-subtle shot across Google's bow, and a sign of further broadband competition to come.

Here's what else is coming, according to a Comcast official:

Later this year, Gigabit Pro will expand beyond Atlanta to cover Comcast's entire customer base — or more specifically, wherever Comcast has laid down fiber. Comcast estimates that 18 million households will become eligible to sign up for the 2 Gbps service, but those households will need to be within one-third of a mile of Comcast's fiber optic infrastructure.

People who have already signed up for Comcast's fastest fiber optic service, which maxes out at 505 megabits per second, will be automatically upgraded to Gigabit Pro, for no extra charge. Gigabit Pro will cost less than the $400 a month that users of the 505 Mbps service currently pay, said the Comcast official, who wasn't authorized to speak publicly. But the company declined to say whether Gigabit Pro would be priced cheap enough to compete directly with Google Fiber, which costs up to $130 a month.

The search giant is famous for offering Google Fiber only to those neighborhoods that express sufficient interest; Comcast, meanwhile, is taking advantage of its existing presence to upgrade speeds for many more people, said Doug Guthrie, the head of Comcast Cable's southern region.

"Our approach is to offer the most comprehensive rollout of multi-gigabit service to the most homes as quickly as possible, not just to certain neighborhoods," said Guthrie in a statement. "Access to Gigabit Pro will give our customers all the broadband capacity they need to stay ahead of future technologies and innovations."

Google Fiber maxes out at 1 Gbps — equivalent to 1,000 megabits per second or 100 times the U.S. average:

At 2 Gbps, Comcast's service would be double what Google Fiber can offer.

Although Google Fiber may stand at a technical disadvantage here, Comcast's deployment could be a long-term win for Google. Analysts have said Google's objective is to threaten existing Internet providers just enough to spur new competition; when Web users opt for faster Internet, they'll use more Google services — and that's Google's ultimate strategy.

We've seen this dynamic play out before. In Austin, Google Fiber spurred a fiber optic arms race with AT&T and other local providers which began offering faster speeds and lower prices. Now it seems Google has opened another battleground.

Atlanta is the new Austin.