UPDATE: Adding comments, spefications, pricing, background.

Apple Computer on Tuesday unveiled at the Macworld conference the first ever x86-based Macintosh computer based on the dual-core processor code-named Yonah designed for the mobile computers. The new iMac is said to be faster compared to the G5-based iMac products released previously.

“The new iMac is two to three times faster than the iMac G5,” said Steve Jobs, Apple’s chief executive during the presentation that took place months ahead of the original schedule.

Apple immediately starts selling 17” and 20” iMac computers based on the Intel Core Duo processors up to 2GHz, 512MB of DDR memory, ATI Radeon X1600 128MB graphics card. The new computers will run Mac OS X Tiger 10.4.4 and will be equipped with Rosetta software that will allow applications developed for PowerPC chips to operate on x86 central processing units.

Each of the two processing engines of the Intel Core Duo processors was claimed to be more powerful compared to single-core IBM G5 chips, while two of such cores enable more efficient multitasking on the iMac computers – Apple’s machines aimed at mainstream customers – for the first time in history.

Pricing of 17” and 20” iMacs is expected to be similar compared to today’s products. The system will retail form-factor and design of the latest iMac computers.

Apple iMac 17” computer with LCD display with 1440x900 resolution, 1.83GHz Intel Core Duo processor, 512MB PC2-5300 (667MHz) DDR2 SDRAM, ATI Radeon X1600 128MB graphics card, 160GB Serial ATA hard drive and slot-load 8x double-layer SuperDrive will cost $1299. Apple iMac 20” with LCD panel with 1680x1050 resolution configured similarly, but with 2.0GHz processor and 250GB storage will be priced at $1699.