Nvidia's new Tegra 2 mobile chips are in tablets and smartphones made by Motorola, LG, Dell, Acer, Asus and Toshiba Corp, a spokesman for the graphics processor designer said.

Shares of Nvidia rose nearly 13 percent on optimism about its chip, which faced setbacks in development, and after news that it is teaming up with ARM to take on semiconductor giant Intel's dominance of personal computers.

At the Consumer Electronics Show in Las Vegas, an Nvidia spokesman said Motorola Mobility was using the Tegra chips in its Atrix 4G phone for AT&T and its Droid Bionic phone for Verizon.

LG Electronics Inc will use them in its Optimus 2X phones.

A lot of people have had some hands-on experiences with it and are really starting to see the tech for what it is, said Wedbush analyst Patrick Wang at the trade show. We've talked about it for a long time, speculated on it, and now it's appearing.

Dell said its 7-inch touchscreen Streak tablet will use Nvidia's chip and run on T-Mobile's high-speed 4G network.

Shares of Nvidia were up 12.7 percent at $19.14 on Thursday, bringing their gain over the past two sessions to about 21 percent.

We view Nvidia as a solid play on Android smartphones and tablets with Tegra potentially adding over $400 million in higher-margin sales in 2011, Barclays Capital analyst Tim Luke said in a note.

Nvidia also said it was using ARM's architecture to build central processors, or CPUs, for personal computers, which could help shake up a market where Intel has an 80 percent share. Revenue gains from that move would be years away.

Besides phones and tablets, Nvidia is pushing to get its silicon into automobiles. It said this week that its graphics processors will be used in the navigation and vehicle information systems in next-generation BMW cars.

(Reporting by Noel Randewich; Editing by Lisa Von Ahn and John Wallace)