Apple Computer sped up its iMac line on Tuesday, adding faster processors and graphics chips along with its just-released Mac OS X Tiger operating system.

The new models, which have the same design as previous G5 iMacs, also feature gigabit Ethernet, Bluetooth and 802.11g wireless networking. The all-in-one desktops also offer improved graphics power with the addition of the ATI Radeon 9600 graphics processor and 128MB of video memory.

"Reviewers have called the iMac G5 'the most elegant desktop computer in the world' and now it's getting even better," Apple senior vice president Phil Schiller said in a statement. "With a faster processor, built-in wireless networking, Tiger and iLife '05, the new iMac G5 offers the best consumer desktop computing experience in the world."

The iMac continues to come in three models. The US$1,299 entry-level version comes with a 1.8GHz chip, a 17-inch wide-screen display, 512MB of memory, a 160GB hard drive and a combo drive that can burn CDs and play DVDs.

The US$1,499 midrange model also has a 17-inch screen and similar size hard drive and memory, but adds a 2GHz processor and a SuperDrive that can burn both CDs and DVDs. The SuperDrive boasts an improved 8x speed over prior Apple models and also has support for double layer discs.

The high-end model sells for US$1,799 and offers a 20-inch screen and a 250GB hard drive.

All of the new models come with Apple's iLife '05 suite as well as the Tiger OS, which went on sale on Friday.

Apple introduced the first G5 iMacs in August, following a delay as the company switched from the prior desk-lamp style G4 iMac.