Power Macs G4 800MHz, 933MHz & 1GHz DP


The unveiling of the new iMac consumer desktops at Macworld Expo San Francisco (see Macworld, February 2002) left Apple’s professional Power Macs looking a bit tired. Even the entry-level iMac sports a 700MHz PowerPC G4 processor – just 33MHz slower than the then low-end Power Mac. With the iMac jumping from G3 to G4, Apple had to differentiate its Power Macs further from the consumer systems. PowerPC developer Motorola has finally offered up just such a point of differentiation – the symbolic crossing of the gigahertz barrier. For at least a year now, Windows PCs have sported Pentium processors that boasted gigahertz (GHz) instead of megahertz (MHz) speeds. Apple protested – with sound scientific backing – that the Intel chips had to run at these seemingly “faster” speeds just to keep-up with Motorola’s apparently slower G4 processors. The “Megahertz Myth”, Apple said, is a phoney because the PowerPC’s architecture is more sophisticated than the Pentium’s. The more “pipeline stages” a chip has, the less efficient it is – and so has to go twice as fast to keep pace with more-efficient PowerPCs. Pentiums have many more “pipeline stages” than the PowerPC – the P4 has 20, compared to the G4’s 7. To push data through a pipeline stage takes no small amount of effort – hence, the manic speeds required to get as much data through 20 as it does through 7. A P4 huffs and puffs at 1.7GHz just to keep level with the whistle-while-jogging 867MHz G4, according to Apple – mightily annoyed that Joe Public was so easily fooled by the bigger-number-is-better argument of the Windows crowd. Now that Motorola has pulled its socks up and started shipping G4s at GHz speeds, Apple can at least look less ashamed when it comes to chip-bragging contests with Compaq, Dell, etc. But as Intel prepares to crank out its first 2GHz chip, Apple had better keep mentioning those performance-choking pipeline stages for a while yet. Macworld speed tests
The GHz barrier is, of course, a milestone purely in terms of numbers. That said, the speed gain is impressive in key areas. In a suite of Photoshop tests, the new top-of-the-range Power Mac’s two 1GHz G4s outperformed the previous 800MHz DP G4 by a whopping 84 per cent. Graphic artists, prepare to get greedy... That’s some jump on what was already a very fast machine. If you’re labouring on a G3 or slower G4, imagine the imaging boost you get with multiprocessing GHz power. As you can see from our speed chart, the other two new Power Macs are also pretty nifty on the thorough set of Photoshop tasks we put the systems through. The 933MHz model is 41 per cent faster than the previous 867MHz model. Even the 800MHz model outperforms that seemingly faster Mac (by some 17 per cent) – we’re not quite sure why: it’s down to performance on Photoshop’s Lighting Effects filter. Multiprocessing MP greatly speeds Photoshop, which is one of relatively few applications specially optimized to take advantage of the two chips. Another app where two is better than one is Cinema 4D XL. 3D rendering times were slashed when using a dual-G4 system. The single-chip Power Macs performed exactly as you’d expect according to their processor speeds. Overall, the new single-800MHz model is slightly slower than the older 867MHz Power Mac – with both eclipsed by the 933MHz system. The previous MP system (dual-800MHz) is 41 per cent faster than the 933MHz model, but the dual-GHz is 39 per cent faster still – that’s 143 per cent faster on this application than the new entry-level machine! Multiprocessing, however, kicks in only when applications are MP-optimized. Other optimized apps include NewTek LightWave, and Apple’s Final Cut Pro. Macworld’s general-tasks tests, which we use to formulate our overall Speedmark score, show how little multiprocessing helps on non-optimized applications – even using Mac OS X, which does get a small boost from the two chips. Ignoring Photoshop et al, the dual-GHz Power Mac is faster than the 933MHz model, but only by 8 per cent. Our Quake III test does demonstrate, however, that two processors greatly boosts frame-rates. Although both feature NVidia’s GeForce4 MX graphics card, the dual-GHz Power Mac can crank-out 150 frames per second, compared to the 933MHz’s 87.7 – a 71 per cent improvement. Quake III is MP-aware, but there's a command that you have to enter for it to work. If you use Photoshop or one of the other optimized apps heavily (or you’re that mad on 3D games), then you should push the boat out for the top, dual-GHz model. If these programs are of peripheral or no interest to you, buy the 800MHz or 933MHz model – and use the saved cash to bump-up the RAM, or go on a weekend break. Cache
As with the last few Power Mac roll-outs, the top two systems feature improvements not included with the entry-level model. The 933MHz and dual-GHz Power Macs receive their performance boost not just from the extra processor speed. Apple has significantly ramped the Level-3 cache – including a massive 2MB of Double Data rate (DDR) RAM per chip running at 500MHz, allowing up to 4GB per second throughput for the cache. All three systems also feature 256K on-chip L2 cache running at the full processor speed. More than the GHz milestone, Apple’s use of this high-speed DDR memory is a real technological advance for the platform. DDR RAM allows data to be sent or retrieved on both the upswing and downswing of the clock cycle, doubling the bandwidth over conventional RAM. Memory
The standard RAM used by all these systems is still PC133 RAM. With three DIMM slots, the maximum memory of the Power Macs is 1.5GB. The 800MHz and 933MHz models ship with 256MB of RAM; the dual-GHz starts with 512MB. Online memory prices – at the time of going to press – are approximately £90 for a 512MB DIMM, £50 for 256MB, and £26 for 128MB – but note our news story on page 24. Even with Mac OS X’s sophisticated memory management, you can’t go wrong buying as much RAM as you can afford. Graphics go for it
Apple hasn’t just upped processor speeds on its new range of Power Macs – graphics cards have also been changed. The standard option on the entry-level 800MHz Power Mac is ATI’s Radeon 7500, which features 32MB of high-speed DDR memory on an AGP 4X card. The new Radeon also uses ATI’s Charisma Engine for integrated hardware transform and lighting, and the Pixel Tapestry engine, that provides per-pixel shading capability. The 933MHz and dual-GHz systems ship with NVidia’s GeForce4 MX, which Apple claims offers performance on a par with high-end visualization workstations. The GeForce4 MX features 64MB of DDR RAM to support larger textures for 3D objects in games and pro apps. According to Apple, it delivers up to 40 per cent more 3D performance than the Radeon 7500. Via the online Apple Store’s Build-to-Order (BTO) option, Apple is now also offering NVidia’s even-more powerful GeForce4 Titanium, which Apple and NVidia claim is “the world’s fastest graphics processor”. Its LightSpeed II memory architecture uses 128MB of fast DDR RAM. It delivers a theoretical memory throughput of 10.56GBps, which can deliver over 87 million triangles and over 4.9 billion textured pixels (texels) per second. Using BTO, adding NVidia’s GeForce4 MX card to the 800MHz model costs £70 more; adding the GeForce4 Titanium to the entry-level model costs an extra £260. Upping the GeForce4MX to the Titanium model costs an extra £190 via BTO. Alternatively, you could save £70 on the top two models by opting for the Radeon instead of the GeForce4 MX. These BTO options are available via the Apple Store only. If you buy from another dealer, you’ll have to swap out the graphics card yourself if you don’t fancy what’s pre-installed. The Radeon 7500 will be fine for most of us, but the GeForce4MX is definitely a step up for 3D artists and serious gamers. The GeForce4 Ti is dreamland for such users. Each card offers built-in dual display support. The Extended Desktop mode allows users to work on two monitors at once for increased desktop real-estate. And Video Mirroring is handy when presenting, so you can see the same image on a projector that you’re seeing on normal display. The Radeon 7500 and GeForce4 MX cards can drive an ADC-based 15-inch or 17-inch Apple Studio Display or 22-inch Cinema Display, as well as any monitor with a VGA connector. The GeForce4 Ti contains both an ADC port and a DVI port, and so can drive two ADC monitors with the addition of a third-party DVI-I to ADC adaptor, such as the Dr. Bott DVIator adaptor (£109 from the Apple Store, 0800 039 1010). It also ships with a DVI-to-VGA adaptor to connect VGA monitors to the card’s DVI port. If you want to have two Apple LCD screens from a new Power Mac without the GeForce4 Titanium, you’ll need to go to the expense of buying a DVI-based video card (an ATI Radeon costs about £150) plus a DVIator adaptor. If you really need this, buy the Titanium card, instead. Drive time
Apple offers its 933MHz and dual-GHz Power Macs with the DVD-R SuperDrive – which can read (24x) and write (8x) CDs, as well as read (6x) and write (2x) DVDs. With the bundled iDVD 2 software (reviewed, January 2002), it’s easy to create discs (via drag-&-drop) that will play in domestic DVD players. Blank DVD discs cost just £3.50 each from Apple (0800 039 1010). The 800MHz model ships with a CD-RW drive that reads CDs at 32x and writes to CD-R at 24x and CD-RW at 10x. Hard-disk capacities stay the same, but the entry-level 40GB disk is now a 7,200rpm model – compared to the previous 733MHz Power Mac’s drive, which span at 5,400rpm. The 60GB and 80GB drives also spin at a reasonable 7,200rpm. Via BTO, Apple also offers 10,000rpm Ultra160 SCSI hard drives, which come with a dual-channel Ultra160 SCSI card installed in one of the computer’s PCI slots. Professional users will find these SCSI disks a lot faster than the ATAs, but the extra cost (at least £500) is enough to put off many. Plus ça change
As explained above, the key new features of the improved G4 Power Macs are increased performance (via faster processor speeds, and the adoption of DDR-RAM on larger chunks of L3 cache), and much-improved graphics cards. There’s not much else changed on the Power Mac range from those unveiled at last July’s Macworld Expo in New York (see Macworld, September 2001). You get the same easily upgradeable ‘Quicksilver’ case, back-mounted ports and connections (two USB, two FireWire, Gigabit Ethernet, four 64-bit, 133MHz PCI slots, pre-filled AGP 4X slot, and built-in 56Kbps modem), and Pro Keyboard and Pro Mouse. The basic motherboard design, with 133MHz system bus, remains unaltered. Apple sticks with ATA-66 storage interface, while many top PC workstations now feature the faster ATA-133. High-end professional users will opt for SCSI or RAID storage, making the ATA issue irrelevant; but the more budget-conscious will suffer slower speeds on large file transfers. The Power Macs also stick with FireWire 1.0 and USB 1.1. To be fair, FireWire 2.0 (or to use its more-proper, but boring, name, IEEE 1394b) – offering at least 800Mbps data-transfer rates as opposed to FireWire 1.0’s 400Mbps – isn’t ready yet. USB 2.0 (up to 480Mbps), on the other hand, is currently out there. As Apple invented FireWire, its loyalties are pretty obvious. It’s a sure bet that all Macs will eventually move over to 1394b when it’s ready and when digital devices start using the new standard – which could reach as far as 3,200Mbps. As for USB 2.0, it would be silly for Apple to now add cost to its range when so few devices out there take advantage of the new Intel standard. Software extras
Power Macs don’t usually come stuffed with software – that’s the preserve of the consumer iMacs and iBooks. But this range has its fair share of free stuff, on top of Mac OS X, OS 9.2.2, Acrobat Reader, FAXstf X, and Internet Explorer 5.1. (Don’t worry about OS X if you’re wary of upgrading right now. Outside of the US, we have to install the operating system ourselves – and so can stick with OS 9, if we wish. Do install OS X, though – if only to have a play around to start with.) Of course, you get Apple’s superb range of digital-hub software, including the new iPhoto for editing, organizing and sharing your digital images. iMovie 2, compatible with most popular DV camcorders, lets you import digital audio and video via FireWire. iTunes makes creating and managing your digital music collection as easy as compiling a tape collection, and links nicely with Apple’s iPod MP3 player. The 933MHz and dual-GHz Power Macs come with iDVD 2 pre-installed, to work with their SuperDrive DVD-R drives. Free software includes Art Directors Toolkit (ADT), which has a bunch of designer-friendly tools – for example, letting you view every possible character in a font, capture the actual colour of a pixel on-screen, converting points to picas, etc. PixelNhance, from Caffeine Software, is a real-time image-enhancement application that lets you quickly determine the best image-adjustment settings for digital images. Many Macworld readers will be familiar with the Snapz Pro 2 screen-capture utility and GraphicConverter. Snapz Pro X supports saving screen images as .bmp, .pict, .gif, .jpg, .png, .tiff, .pdf and Photoshop files, and also records animated or action sequences as a QuickTime movie. GraphicConverter lets you import images from over 100 graphic file formats – and export to dozens of graphic file formats. OmniGraffle helps you to draw diagrams, family trees, flow charts and layouts. OmniOutliner maintains multiple to-do lists, and tracks items such as the books or DVD movies in your personal library. PCalc 2 is a full-featured scientific calculator with support for hexadecimal, octal and binary calculations, and that also includes a Reverse Polish Notation (RPN) mode.
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