Apple Purposely Slows MacBook Pro Graphics

The graphics processor of Apple Computer Inc.'s MacBook Pro portable has been deliberately slowed down, a Mac user reported recently, probably as part of the overall effort to lower the heat the machine generates.

According to a posting on the French language site MacBidouille, a user identified as "SpacetitoX" uncovered the underclocking of the MacBook's ATI Radeon Mobility X1600 graphics chip after adding Windows XP to the computer, then running a beta version of the "ATITools" overclocking utility.

Apple's Intel-powered iMacs use the same ATI GPU as the MacBook.

SpacetitoX clocked the graphics processor (GPU) at 310MHz, 35 percent slower then ATI's recommended 475MHz. He also clocked the MacBook's graphics RAM at 278MHz, 41 percent below the 470MHz par ATI tells system makers to use.

By replacing the existing ATI drivers added to the MacBook Pro for dual-booting into Windows XP, SpacetitoX was able to boost one benchmark's result from 61 frames per second to 91.The theory is that Apple's underclocked the GPU and its memory to reduce heat inside the portable. Like most notebooks, the MacBook uses a fan, and other techniques, to dissipate heat generated by the CPU, graphics card, and other electrical components, but Apple has made a point of stressing how quiet its Intel-based computers are, in part due to the use of low-powered components.

It also touts the MacBook Pro's cooler design. "In the world of notebooks, there’s an eternal struggle between the forces of design and the forces of thermodynamic reality," Apple's Web site reads. "MacBook Pro innovates its way to a better place."

Ironically, in the next breath, Apple brags about performance. "Not only are its parts engineered to squeeze out every last joule of performance, they’re meticulously placed to minimize size. The result? Ultra performance in a thin, light package."

MacBook Pro users have posted heat-related complaints to Apple's official forums since early March, not long after the portable's debut, with some claiming that the computer is literally too hot to handle at times.

"I thought my notebook was defective and complained to apple," wrote someone identified as "zicobee." "I was told the heat is to be expected in view of the thin size of the notebook. They casually told me that that is why it is called a notebook and not a laptop!"Apple did not immediately respond to a request for comment on the underclocking claims.

SpacetitoX has made several patches and utilities available for download from a Web site, but asks for a donation of at least 1 euro via PayPal.