said it is shifting its top-end Power
Mac family to support only dual 64-bit PowerPC G5 processors in an effort to
bolster its presence in the professional marketplace.
The Cupertino, Calif.,-based computer maker introduced the three new Power
Macs Wednesday. The fastest features two 2.5 GHz processors and a 1.25 GHz per
processor front side bus, and it is partially cooled by a combination of water
and propylene glycol, a clear liquid used in automobile antifreeze.
Internal fans and an open grill enclosure help cool the other two
models – a dual 1.8 GHz Power Mac and a 2.0 GHz version.
“It’s a completely maintenance free system,” Tom Boger, Apple senior
director of desktop product marketing, told internetnews.com. “The
processor was built using the 90-nanometer process. When you do that, you
challenge the power density. You could see the same problem happening with
Intel’s 90-nanometer chips.”
The cooling technique is nothing new. For years, computer enthusiasts and
gamers have used various refrigeration techniques, including the use of
ethylene glycol or propylene glycol to reduce surface temperature on
hot-running chips. Running at top speed, some Mac users report their G5
machines run at temps of 85 Celsius or 185 Fahrenheit. Apple said it
designed its G5 systems so that the fluid encircles the two G5 processors
and transfers heat from the chips as they work harder. The computers are
outfitted with 21 different temperature sensor points to help monitor the
Apple said speed is not the only factor in the design of its systems, but
boasted that its 2.5GHz ran significantly faster than Intel’s 3.4 GHz
Pentium 4 systems in benchmark tests of Adobe Photoshop, Logic Pro 6, and
Final Cut Pro.
Boger said that it was very unlikely that the G5 processor would appear
in its PowerBook laptops before the end of the year, but reiterated that
Apple continues to work with its G5 PowerPC chip supplier IBM on the
challenges of process technology.
As for the future, Apple declined to speculate on potential
configurations, including producing a four-processor or 4-way system for
either its Power Mac or Xserve families. The company has long held itself as
a competitor against Dell
systems as far as value and
performance. Adding a 4-way product for Apple could re-ignite that rivalry.
The new G5s come standard with an 8x SuperDrive and either the NVIDIA
GeForceFX 5200 Ultra or the ATI Radeon 9600 XT graphics card. The top two
models also include three PCI-X
The dual 1.8 GHz, (starting at $1,999) and dual 2.0 GHz Power Mac G5
models are available now. The dual 2.5 GHz version ($2,999) is expected
to be available in July. Apple said it would discontinue production of its
current Power Mac G4s and sell off its related inventories.