After Steve Jobs announced Apple ’s program to drop the PowerPC processor and put Intel inside succeeding Macs , some performance - hungry pro fear they ’d see no major advances in Mac processing speed until the arrival of an all - unexampled , Intel - base line of high - ending desktop models — something that could be a year or more away , according to the company ’s modulation timetable .
Cross that one off your worry tilt . With the introduction of the Power Mac G5 / Quad-2.5GHz , Apple has delivered the biggest jump in Mac carrying out in years — not for every app , but the character for which this machine was design . The Quad excels at the computation - intensive , multiprocessor - savvy programs commonly used in field such as scientific computation , professional audio and video recording and similarly demanding environments .
Gang of four
The speeding discovery is not the consequence of a sudden surge in G5 clock swiftness — two and a one-half years after the first G5s debuted at speed of up to 2GHz , IBM , Apple ’s chip supplier , still has n’t stumble the 3GHz chump . In fact , at 2.5GHz , the Quad ’s two G5s really run a shade slower than the 2.7GHz chips that power the late top - of - the - line Mac .
The remainder is that the Quad ’s processors are a new version of the PowerPC that invest two G5 processing building block — known as “ cores ” — on each Saratoga chip . Each gist has all the features of late G5 chips , including a Velocity Engine to accelerate scientific and multimedia system data processing , a 32 KiB Level 1 cache for ultra - fast access to recently used data , and an every bit rapid 64 K Level 1 cache for instructions . In addition , each substance in the unexampled G5 chips has a full M of Level 2 hoard retention , compared to 512 G per chip in the previous G5 generation .
The other two young screen background models announced alongside the Quad , the 2.0GHz dual - core Power Mac G5 and the 2.3GHz dual - core Power Mac G5 , use like duple - meat CPU , but those systems have only one chip apiece . With two dual - substance processor , the Quad has — as its name is intended to suggest — the equivalent of four standard G5 chips , twice as many as any old Apple organization . ( consecrate collectors of Mac minutiae may recall , however , that erstwhile clone - maker DayStar Digital marketeda organisation with four PowerPC 604e chips , at speeds ranging up to 233MHz , for a few month in 1997 . )
Just as Mac OS X divides chores between the two CPUs in older duple - CPU Power Macs and between the two processing engines in the new single - chip , dual - gist G5 systems , all four locomotive in the Quad can share the freight . One expert trade-off in the system ’s designing : in previous Power Mac G5s , each CPU had its own frontside motorcoach to transport data and operating instructions to and from retentivity , while in the new models , the two cores in each chip have to share a bus . But the new chip shot ’ expatiate L2 caches help to indemnify : with more information already on helping hand in the cache , the cores do n’t ask to deform to the bus as often . And when they do , a faster memory scheme should ensure that the bus gets loaded in a hurry . The Quad , like its single - processor dual - core siblings , uses 533MHz DDR2 ( double information charge per unit two ) , also known as PC2 - 4200 , memory , compared with the 400MHz DDR chips in the old models .
Net effect
If you give just a spry glance at the Macworld Lab benchmark results for the Quad , you might wonder what the fuss is all about — on the Speedmark psychometric test suite , the new scheme barely managed to inch out the previous Mac carrying out champ , the 2.7GHz three-fold - central processor model , and look at that the Quad has twice as much sensitive processing power as its undivided - chip , twofold - nucleus sib , its lead over them is surprisingly modest .
Quad-Core Power Mac Tested
respectable results in bold . Reference scheme in italics .
Speedmark 4 score are relative to those of a 1.25GHz Mac miniskirt , which is assigned a grudge of 100 . Adobe Photoshop , Cinema 4D XL , iMovie , and iTunes scores are in minutes : seconds . All systems were pass Mac OS X 10.4.3 with 512 MB of RAM , with processor performance place to Highest in the Energy Saver preference pane . We converted 45 minutes of AAC audio files to MP3 using iTunes ’ High Quality setting . We used Unreal Tournament 2004 ’s Antalus Botmatch average - skeleton - per - indorsement score ; we test at a solvent of 1,024 by 768 pel at the Maximum setting . The Photoshop Suite trial is a set of 14 scripted tasks using a 50 Mbit file . Photoshop ’s retention was set to 70 percent and History was set to Minimum . To liken Speedmark 4 scores for various Mac systems , visit our Apple Hardware Guide .—Macworld laboratory examination by James Galbraith and Jerry Jung
A closer facial expression at the termination , however , shows why the Quad really is a big deal — for the markets it was design to serve . On many of the real - humans tasks that make up the Speedmark entourage , the Quad only marginally outperformed the other model we test ; on six of the 15 test , it even lagged somewhat behind the 2.7GHz dual - central processing unit organization .
That ’s because many of the tasks timed in Speedmark , such as starting up the system , depend more on other components — particularly the hard ride — than on the available processing engines ; other Speedmark tests use applications , such as Apple ’s own consumer - oriented iTunes and iMovie , that have n’t been optimized for multiprocessor system of rules . Even our Photoshop CS2 trial run , a exercise set of 14 written tasks using a 50 M image , showed a speedup of less than 10 percent relative to the 2.7GHz dual - processor Power Mac , even though past examination has prove that Photoshop benefits greatly from threefold - mainframe ironware .
A few ofMacworld ’s science laboratory tests , however , show the sensational improvements we ’d hoped for from the Quad . In our standard interlingual rendition test with Maxon ’s Cinema 4DXL 9.1 , the Quad demand only 37 seconds to handle a task that took 63 seconds on the 2.7GHz dual - mainframe Mac , 71 seconds on the recently released 2.3GHz dual - core Power Mac , and 83.3 seconds on the new 2GHz treble - substance mannikin . In a separate test ( not part of the Speedmark cortege ) that involves encoding TV into MPEG-2 format with Apple ’s Compressor utility , the Quad start the job done in just 3 second and 23 mo , whereas the 2.7GHz dual - processor system of rules want 5 minutes and 12 seconds , the 2.3GHz dual - effect need 5 second and 35 second , and the 2GHz dual - heart model , at 6 moment and 20 seconds , take on almost twice as long as the Quad .
Those are huge clip - delivery , the form that can convince even tightwad corporate attic heel counter to authorize trade up to young computer hardware . And these are n’t just isolate examples — Apple has a whole serial ofin - house testsshowing the Quad outmatch the 2.7GHz dual - processor example .
The lesson of all this : the benefits of the Quad , even more than old Macs , depend on the diligence you run and the tasks you perform most frequently . On some task in some programme , those benefits might not apologize investment funds in a Quad . But for applications that have been fully optimized for multiprocessing — particularly curriculum that make heavy use of the G5 Velocity Engine — and for users who seek to carry multiple computation - intensive programs at the same time , the Quad may quickly devote for itself in spades .
Processing isn’t everything
Besides , the Quad ’s four G5 inwardness are not its only magnet . As our Unreal Tournament 2004 frame - rate test suggests , the graphics card that ’s standard in the motorcar ’s 16 - lane PCI Express slot — the Nvidia GeForce 6600 with 256 MB of dedicated memory — delivers great legal action video . And the two other Nvidia graphics cards Apple offers as upgrade option for the Quad — the GeForce 7800 GT with 256 MB of storage ( $ 350 ) and the two - slot Quadro FX 4500 with 512 M of memory board ( $ 1,650 ) , which supports two 30 - column inch Apple Cinema HD displays plus stereo 3D goggles — undoubtedly execute even easily , both with biz and with scientific visualization diligence .
In addition , the Quad , like the dual - marrow Power Mac G5s , declare oneself all the advanced lineament that user are used to , including FireWire 800 as well as 400 port ; a SuperDrive , now running at up to 16x and supporting two-fold - bed combustion ; and digital optical sound in and out jack . The Quad also sport major sweetening over previous modelling that are train at users who work out on particularly demanding tasks and need the most modern networking , reposition , and expansion technology available . It has room for up to 16 GB of memory ( with musical accompaniment for ECC — error - rectify computer code — RAM if it ’s needed ) , three free PCI Express slot ( one eight - lane , two four - lane ) , and dual Gigabit Ethernet port , offer musical accompaniment for Apple ’s Xsan memory board system and for throughput - boosting features such as jumbo frames .
Sound of speed
One bill of caution : I found the Quad somewhat quiet in quotidian operation , but when you push it — in particular , by guide chore that keep all four G5 cores cranking — the fan sound off in to aid the liquid cool arrangement . You ’ll in spades hear , and peradventure even feel , the resulting whoosh . The Quad engage within the same dB range as premature Power Mac G5s , according to Apple , but when you get near to the high end of that cooking stove , the noise can be jolly intense .
Macworld’s buying advice
The note value of the Power Mac G5 / Quad-2.5GHz depends on what you do with it . With many app , it ’s merely the fast Mac yet , but not by much , and the difference might not be enough to absolve the expense . On the other script , for user of many high - goal media - processing and scientific applications — especially those who also desire to apply the late expansion , networking , and memory technologies — the Quad adds up to a terrific advance in Mac power , one well deserving the Leontyne Price .
[ Henry Norr is a former editor ofMacWeek . He has been review Mac organization since 1986 . ]
