Apple used Macworld Expo New York 2001 to introduce its most-powerful line-up of G4 Power Macs yet, with 733MHz, 867MHz and dual-800 MHz models, increased use of the DVD-R SuperDrive, and a new silver casing for the professional desktop minitower.

The second-generation Power Mac G4 is code-named "Quicksilver" because of its super-fast processors and its new silver casing that replaces the classic Graphite colour.

Faster than a 1.7GHz Pentium 4 Apple claims that – under testing of commonly used operations in Adobe Photoshop 6.0 - the 800MHz DP Power Mac runs up to 83 per cent faster than a 1.7GHz Pentium 4-based PC (tested: IBM NetVista Alta PC workstation). Apple’s vice president of worldwide product marketing Phil Schiller called the new multiprocessor Mac "Apple's new bad dog".

Apple claims that the single-processor 867MHz Power Mac G4 is 58 per cent faster than the 1.7GHz Windows machine, with the 733MHz model still 33 per cent faster than the PC.

During his Expo keynote, Apple CEO Steve Jobs invited Schiller on to the stage for a now-familiar showdown between the fastest G4 chip and the fastest-available Intel processor. The 867MHz G4 trounced the 1.7GHz P4 on real-world tests involving Media Cleaner 5 (encoding the QuickTime trailer for the upcoming 'Spiderman' movie) and Photoshop (building a poster for Pixar's 'Monsters Inc'). What took the G4 45 seconds took 82 seconds on the P4.

Steve Jobs brought Apple senior VP of hardware Jon Rubinstein to debunk the "Megahertz Myth" – by which people mistake the quoted number of megahertz a processor runs on as comparable between chips and platforms. Rubenstein used simple moving graphics to explain the architectural tradeoffs – such as 'Pipeline Tax' in chip design.

"The G4 is an extremely efficient design, with a third of the pipeline segments of the Pentium 4," Rubenstein told the audience. Intel's forthcoming Itanium chip will be closer to the G4 in pipeline segments, and so will be faster than the P4 despite reaching just 800MHz at launch.

Feature sets Nvidia's 32MB GeForce2 MX graphics card is standard in all the models' 4x AGP slot – except for the 800MHZ DP, which ships with the new 64MB GeForce2 MX with TwinView card for dual-monitor support standard in the 800MHz DP model. This lets you connect both an Apple display (using the Apple Display Connector) and a VGA display - without using an additional graphics card.

You can also get Nvidia's GeForce3 graphics card with 64MB of DDR RAM as a build-to-order option from the Apple Store for an extra £260 (ex. VAT).

Each AirPort-ready Power Mac also features two FireWire and USB ports; four full-length 64-bit PCI slots; 10/100/1000BaseT Ethernet, built-in 56K V.90 modem; three 3.5-inch hard-disk expansion bays (with one pre-installed Ultra ATA hard drive); and iDVD, iTunes and iMovie 2 software. Both Mac OS X and Mac OS 9.1 are pre-installed in all models.

Both the 867MHz and dual-800MHz processors include 256K of on-chip level-2 cache running at processor speed, and 2MB of level-3 backside cache per processor.

The SuperDrive writes DVD-R at 2x, reads DVD at 4x, writes CD-R at 8x, writes CD-RW at 4x and reads CD at 24x. Apple's SuperDrive is not available with the 733MHz system - but, via the online Apple Store, you can choose a DVD-ROM/CD-RW combo drive for an extra £110 (ex. VAT).

Model by model The new Power Mac G4s are available in three standard configurations.

The 733MHz Power Mac G4, costing £1,199 (excluding VAT), includes: 128MB of RAM; a 40GB Ultra ATA/66 hard disk; CD-RW drive; and 256K on-chip level 2 backside cache.

The 867MHz Power Mac G4, costing £1,799 (ex. VAT), includes: 128MB of RAM; 60GB hard disk; and SuperDrive combination CD-RW/DVD-R drive.

The dual-800MHz Power Mac G4, costing £2,499 (ex. VAT), includes: 256MB of RAM; 80GB hard disk; and SuperDrive combination CD-RW/DVD-R drive.

Availability The new 733MHz and 867MHz Power Mac G4s are available immediately, with the 800MHz DP expected in August.