Intel has been slowly rolling out the latest batch of its Core i5 and i7 processors. Consumer Reports has just rated several laptops and desktops that use this third-generation series, and we've found that they boost performance up to 20 percent for certain tasks compared with the previous generation's same speed Core processors..

Formatting music from CD to MP3 with these processors was faster, compared with doing the same on second-generation Core processors. Video files also converted more quickly from one format to another—and if you have programs that work specifically with the new processors, you can get even a bigger speed boost. Photo uploads were faster, and video quality while watching movies was also slightly better.

New 3D features were also added to the new processors by Intel, including the ability to watch 3D videos with passive glasses and faster conversion of 2D videos into 3D.

If your main focus is on productivity applications such as Word and Excel, you're less likely to see any performance improvements with the new processors, as programs like that are already as fast as they need to be.

We recommended all but one of the computers we tested with the new processors, as all were excellent performers. (The one we didn't recommend was too heavy for a laptop.) Since this new batch of systems uses the highest-end new processors in this series, they are more costly than other models in our computer Ratings. But they also include larger amounts of RAM and video memory than systems with lower-cost processors.

You can identify computers with the new processor when you check the specs, by looking for a 3 at the start of the four-digit number after Core i5 or i7. Models that start with a 2 use second-generation processors.