An in-depth look at ATI's Mobility Radeon 7500

Today ATI Technologies Inc. unveiled its latest mobile graphics processor, the Mobility Radeon 7500. To find out more about how the new system works and how it differs from technology currently found in Apple's PowerBooks and iBooks, MacCentral talked with ATI's Reuben Soraya -- the marketing director of ATI's mobile business unit.

Now with hardware T&L

The Mobility Radeon 7500's feature list reads like a desktop card. It sports the Charisma Engine, ATI's geometry engine for 3D graphics. It also features Pixel Tapestry, which enables the chip to render 3D special effects and texture processing. ATI's Video Immersion technology provides support for DVD and video playback and device connectivity, and HyperZ helps to conserve memory bandwidth by up to 20 percent.

Soraya said that the Mobility Radeon 7500 uses the same core 3D engine as the recently introduced Radeon 7500 desktop card. "That's where the similarity ends," said Soraya. The Mobility Radeon 7500 sports an architecture that's otherwise highly optimized for the mobile computing environment.

Because the chip is based on the Radeon 7500's 3D core, certain technologies found in the recently introduced Radeon 8500 desktop card -- SmoothVision anti-aliasing, TruForm higher order geometry processing and SmartShader pixel and vertex shading support, for example -- are not present. Regardless, ATI has made some significant enhancements in the Radeon Mobility architecture with this product introduction, especially for 3D application users and game fans.

This is the second-generation Mobility Radeon chip, and it's the first to feature hardware transform & lighting capabilities. Such functionality will enable the Mobility Radeon 7500 to display much faster graphics for some 3D games and applications. Soraya said that ATI's benchmarks show the Mobility Radeon 7500 yields almost twice the frame rate in Quake 3 Arena when compared to a similar system equipped with Nvidia's first mobile processor, the GeForce2 Go. Hardware T&L isn't limited to games -- it's something that can benefit other 3D applications, as well.

Power conservation, emissions reduction, video enhancements

The original Mobility Radeon is a fairly power-conservative architecture -- in fact, the system produces less heat and consumes less power than the RAGE Mobility 128 chipset now integrated in PowerBook G4s and iBooks. But with the addition of computationally intensive hardware T&L and other potential power draws, ATI has sought to figure out new and creative ways to make this new mobile chipset conserve as much juice as possible.

The solution is called PowerPlay. PowerPlay introduces the ability for the chip to automatically adjust frequency and voltage settings to help conserve power. The chip can throttle voltage and frequency when switching from a wall jack to battery power, for example. It can reset its power requirements to provide optimal settings for 2D or 3D graphics work, or to play back DVDs. Overall, this can help to extend battery life up to 25 percent, according to ATI. In fact, PowerPlay can even change the laptop computer's LCD panel refresh rate, when supported.

Although users can control various aspects of the graphics chip's performance, most of these changes happen without any involvement from the user at all. And they happen in just few milliseconds, to impact performance as little as possible -- The Mobility Radeon 7500 monitors power consumption and can adjust performance as necessary on a constant basis.

And while this has no bearing on the end-user's experience, Soraya also mentioned that the chip integrates spread spectrum technology -- an emissions reduction technology that up until now laptop computer makers have had to compensate for by installing additional hardware. "It's important to laptop makers because it means that they don't need to install another chip to fix it. We are helping the laptop makers to more easily overcome the [electromagnetic interference] problem."

Mobility Radeon 7500's Video Immersion support means that DVDs look better than before -- the system features on-chip motion compensation and adaptive interlacing. It is also capable of decoding and displaying DVD content in two different HDTV formats -- 1280 x 720 progressive, and 1920 x 1080 interlaced. Because the Mobility Radeon 7500 also features DVI support, this could pave the way for future laptops based on the new chip to offer HDTV output through a component adaptor connected to a DVI interface -- a feature also supported on newer Radeon cards.

Comes in three flavors

ATI has developed three different variants of the Mobility Radeon 7500. The first configuration is a graphics-only variant, which leaves it up to the laptop maker to install graphics memory on the motherboard to support the chip. ATI also has versions with an integrated 16MB frame buffer and a 32MB frame buffer as well -- and up to 32MB of additional graphics memory can be supported on the laptop, for a total of up to 64MB.

Despite the encroachment of players like Nvidia Corp., ATI has a secure hold on the laptop market, according to Soraya. Soraya said that a recent market research study showed that ATI held more than half the marketshare for mobile graphics chips at the end of second quarter. In fact, ATI's products are used exclusively across Apple's portable lines -- both the iBook and the PowerBook G4 feature ATI's RAGE Mobility 128 graphics processor equipped with 8MB of SDRAM.

Speaking of the Mac ...

So with ATI's marketing muscle in the mobile graphics space and the new innovations in the Mobility Radeon 7500, will this new chip come to Apple's portable line? Apple won't say a word prior to a formal product introduction. And as MacCentral went to press with this article, ATI hasn't announced any manufacturing partnerships involving the new graphics hardware on the PC end either, although such announcements are expected soon.

Like other Radeon hardware, ATI has certainly taken Apple into consideration for the new chip. Soraya confirmed that the Mobility Radeon 7500 could be integrated into the Mac architecture quite effectively if Apple wills it. When pressed for details about possible partnerships with Apple, Soraya diplomatically replied, "We have worked closely with key laptop OEMs to develop the new Mobility Radeon 7500."

Noting that the new mobile hardware is production-ready, Soraya suggested ATI's new chip would begin to show up in shipping laptops some time in the fourth calendar quarter of this year.

This story, "An in-depth look at ATI's Mobility Radeon 7500" was originally published by PCWorld.

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