New Power Mac G4s
IntroductionWhile Apple has redesigned and added G4 chips to its PowerBook range, it has taken a different approach to updating its desktop professional systems. On the outside, nothing seems to have changed – the new G4 Power Macs look just like the old ones. But Apple has made significant changes inside the box – improving the logic board and memory controller, upgrading the processors and graphics chips, and adding an extra PCI slot. There’s also CD-RW where once there was a DVD-ROM drive, and an amazing DVD-R SuperDrive where once there was DVD-RAM. New models
As ever, Apple differentiates its Power Mac models by speed of processor. So there are now four basic systems to choose from, as well a dual-processor model. The entry-level Power Mac now boasts a 466MHz G4 processor. This system retains the 16MB ATI Rage 128 Pro graphics card that shipped with the previous series of Power Macs. Memory is doubled to 128MB, as this is Apple’s recommended RAM amount to properly run its forthcoming Mac OS X operating system. And the hard drive is now up to 30GB (using a 5,400rpm Ultra ATA/66 drive). This model costs £1,199, excluding VAT. One model up is the 533MHz Power Mac (£1,599), which drops the Rage Pro for Nvidia’s 32MB GeForce2 graphics card, which delivers improved 2D and 3D graphics rendering. RAM is also 128MB, but the hard drive increases to 40GB (7,200rpm Ultra ATA/66). You can also buy a version of this model that’s powered by two 533MHz G4 chips. Although Apple re-introduced multiprocessing (MP) systems back in July 2000, the company seems to have gone partially cold on them again. This is almost certainly because of a shortage of the fastest chips – clearly there are plenty of 533MHz chips out there, but not that many 733MHz processors. Multiprocessing speeds up software programs that have been rewritten to take advantage of a Mac with more than one chip in it. In Macworld Lab tests on the older 500MHz DP (dual-processor) Power Mac, we found the DP systems to be up to 60 per cent faster than their single-processor equivalents at several key Adobe Photoshop functions – but no faster running non-optimized applications. Mac OS X will be much more conducive to MP Macs, so this model (costing only an extra £210) is well-worth considering if you use Photoshop a lot and are considering an early switch to Mac OS X from the end of March. For more details on MP systems, see our feature in October 2000. After the MP fun, Apple offers a 667MHz Power Mac with 256MB of RAM, 60GB hard drive (7,200rpm Ultra ATA/66), and GeForce2 MX. This £1,999 model won’t be available in the UK until March. Also unavailable until then is Apple’s top-end 733MHz Power Mac – which has the same amount of RAM and hard-disk space as the 667MHz model. It also features the GeForce2 as its graphics accelerator, and will cost £2,499. Apple claims that the 733MHz Power Mac is 38 per cent faster than the previous fastest 500MHz G4, and 57 per cent faster than a 1.5GHz Pentium 4 Windows PC (using a sample of 120 Photoshop filters). Additions and subtractions
More slots When Apple improved the logic board’s memory controller (see box-out “Inside the box“), it was then able to remove the PCI bridge and use the space to add a fourth PCI slot. So now there’s room in all the new Power Macs to add an extra video card or SCSI card on top of the cards you already own. The GeForce2 – or Rage 128 Pro in the case of the 466MHz model – is placed in the AGP slot – newly upgraded from 2x to 4x. This is where the new Power Macs do differ externally from their predecessors, if only at the back – see the photo “Back to back” on the next page. Audio issues
Apple has added a proprietary 16-bit connector, the Apple speaker minijack, for use with its new Pro Speakers. Otherwise, the optional speakers (£39) are the same USB-based Harman-Kardon speakers that ship with the G4 Cube. The sound system on the motherboard itself now has a 20W digital amplifier, driving the headphone output and the output for the new minijack. The headphone output is a standard 16-bit analogue jack that can support other third-party speakers. However, as with the Cube, Apple has removed the analogue microphone jack. Apple claims that the Power Mac G4 supports audio input from USB microphones, and that most users are using those instead of older analogue mics anyway. Bus speeds and cache
As discussed in more detail in the box “Inside the box“, Apple has improved system and memory bus speeds from 100MHz to 133MHz in all the new Power Macs. The 667MHz and 733MHz models also feature new on-chip 256K level-2 cache and 1MB backside level-3 cache (see box “Not just faster – new chips”). The 466MHz and 533MHz models have 1MB of level-2 cache. Networking remains at the impressive Gigabit Ethernet (1,000BaseT) introduced in the Power Macs last July. Software
The new Power Macs come with Mac OS 9.1, iMovie 2, iTunes and the usual Internet browser, email and Palm clients. The 733MHz model also ships with iDVD authoring and encoding software. Speed tests We tested both the single-processor G4 Power Macs that are available to buy today: the 466MHz and 533MHz models. While the 533MHz system is just 7 per cent faster than the old top-end 500MHz G4 in overall performance terms, its Quake III frame rates are an amazing 61 per cent better (see “New Power Mac G4s tested”). The new Nvidia GeForce2 MX clearly rocks at 32MB, while the few extra megahertz and faster system bus have notched performance levels to an expected level. Although its processor runs 34MHz slower than the previous top-end system, the 466MHz entry-level G4 Power Mac nearly exactly matches the old 500MHz model – put that down to the 133MHz bus. The graphics don’t take-off like the 533MHz model’s because Apple has kept ATI’s 16MB Rage 128 Pro graphics card for this system.