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Feature
Eviscerating the Xbox 360 Elite
Prying Eyes examines the engineering inside the 'Elite' upgrade of the popular game console.
By Brian Dipert, Senior Technical Editor -- EDN, 7/19/2007
In late April, Microsoft refreshed its nearly 1.5 year old Xbox 360 product line with the high-end Elite variant, touting an upgraded-capacity 120-Gbyte HDD and an HDMI v1.2 digital audio-and-video interface. When you crack open the Elite's sleek black case, what (if any) alterations to the initial console design will you discover, beyond the HDMI augmentation?
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That very question immediately came to mind when my Xbox 360 Elite review system arrived: This console was begging for Prying Eyes inspection. However, my enthusiasm dimmed when I began perusing others' disassembly instructions and experiences (see, for example, the writeups from AnandTech and ExtremeTech, and the video clip from Semiconductor Insights). My confidence in being able to reassemble the console in a fully functional manner for use in future editorial opportunities was, frankly, (more than) a bit shaky, especially since I wanted to peer underneath the CPU and GPU's heat sinks.
Instead, I contacted the original Xbox 360 Elite disassemblers, the folks at Llamma.com, who'd scored an Elite at a nearby Wal-Mart (make sure you also peruse parts 2 and 3 of their coverage) 10 days before the console's official unveiling. They agreed to share their images with me, one of which appeared in the print version of this EDN article, and many many more of which you'll find in the gallery on this page and referenced in the following paragraphs. I'm very grateful to Llamma.com for working with me on this project; not only does the company offer products and resources for the Xbox 360, its site also covers the first-generation Xbox, Nintendo's Wii, and Sony's PlayStation 2, PlayStation 3, and PlayStation Portable.
Remove the system board from the console, strip away the microprocessor and graphics chip's respective heat sinks, and you're left with a clear view of the PCB. For contrast, here's the system board found in the Xbox 360 Core and Premium models. Thanks to Llamma.com, I also have images of the CPU-specific backside areas of the Elite and Core/Premium PCBs to share with you.
You'll find no discrete boot memory IC in the Xbox 360; Microsoft learned a painful lesson from the hacker community on the first-generation Xbox, whose exposed traces between the CPU and flash memory proved to be an Achilles' Heel. This time around, the system firmware is embedded within the CPU. The boot code's in-system upgradeable, judging from the company's stealth-update response to a hypervisor vulnerability uncovered last fall.
Pry away the heatsink and you'll discover that the GPU is a multidie module comprising the graphics processor and a separate 10-Mbyte frame buffer memory IC. Cross-section analysis by Semiconductor Insights suggests that neither the CPU nor GPU has yet undergone a 90-to-65-nm lithography shrink; single-IC GPU integration is one possible outcome of the 65-nm conversion slated for later this year. Reduced power consumption (and reduced heat generation) is another likely benefit of the pending process transition. In the interim, Microsoft has addressed a common console failure mechanism, heat-induced PCB warping that leads to solder joint failure, by epoxy-bonding both the CPU and GPU to the motherboard.
The bulk of system memory takes the form of 512 Mbytes of GDDR3 SDRAM. Four of the 512-Mbit ICs (multisourced from Qimonda and Samsung) locate on the PCB topside; the other four are mirror-image mounted on the motherboard backside (here are underside overview shots of the Elite and Core/Premium system boards). Since the Xbox 360 comes in an HDD-less Core variant, a Hynix 128-Mbit NAND flash memory serves as an alternate storage location for operating system patches and other code and data updates. Some versions of the motherboard, albeit not the ones shown in this writeup, also include a 2-kbit Atmel EEPROM directly below the CPU.
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The Xbox 360's hardware scaler represents the single biggest evolution in the system design transition from the Core and Premium Xbox 360 models to the Elite version, as well being as a notable differentiation from the hardware-scaler-function-deficient Sony PlayStation 3. Microsoft uses the scaler to up- and down-res, as well as to interlace and de-interlace, game and video content to match the connected display's desired attributes. The first-generation "Ana" scaler IC embeds the necessary DACs for various analog video connections; the second-generation "Hana" scaler (H=HDMI?) on the Elite board presumably also integrates the HDMI transmitter and therefore has access to both the digital video and audio data coming from other system ICs. Missing from the Elite motherboard is a Cypress clock generator IC that was just to the left of Ana; the Ana to Hana transition is also marked by a migration from TQFP to BGA packaging for the scaler IC.
Earlier, I mentioned the heat-related reliability issues that currently plague the console, the long-term fix in the form of cooler-running 65 nm versions of key system ICs, and interim patches such as the epoxy-laminating of the CPU and GPU to the PCB. Shortly before this writeup was published, Microsoft announced that it was taking an estimated $1.05 billion to $1.15 billion charge against its fourth-fiscal-quarter corporate profits, reflective of its decision to extend the console warranty to three years for a specific "three red ring" error message indicating a general hardware error (and widely believed to reflect the earlier-mentioned CPU or, more commonly, GPU solder de-bonding from the PCB…an issue, which in fairness, isn't restricted to Microsoft products).
Interestingly, consoles sent in for repair are being returned with a beefed-up heat sink and airflow pipe assembly. The surmised root issue, which, if true, the revised cooling system addresses, is that the original hardware design unduly restricts airflow across the GPU, which is located underneath the system's also-hot-while-in-use DVD-ROM drive. Not only does the revised design more directly route cool air over both the CPU and GPU, it also appends a heat sink to the previously naked south bridge IC.
I'll close with a calibration-check. After tearing apart the Xbox 360, PlayStation 3 and Wii, the folks at Semiconductor Insights took their dissection tools to an Atari 2600. Check out the YouTube clip and see, as the company's teardown overview page suggests, "just how far gaming technology has come over the past 30 years."
Editor's note
This article appears in abbreviated form in the July 19, 2007 issue of EDN. View/download the printed version (PDF).
Author information
You can reach Senior Technical Editor Brian Dipert—author of the popular blog Brian's Brain—at 916-760-0159 or bdipert@edn.com.
