There is an ungreen revolution taking place in enthusiast game PC circles.
A 1,250-watt power supply--this one from Cooler Master--is the largest a game PC maker will install today.
(Credit: Cooler Master)The eye-opening graphics possible on today's game PCs come at a cost: light-dimming power consumption. The trend, rooted in the perennial quest for more speed, bucks the overall greening of the PC industry.
Green PC designs have become more than just practical; they're cool. Power-sipping Netbooks are in, as are small desktops like the Dell Studio Hybrid and Hewlett-Packard Pavilion Slimline.
This is not the case for high-end gaming PCs, where bigger is better. How far this trend can go isn't clear, but a seminal event in Apple's history may offer a lesson. In 2001, Apple unveiled one of the first dual-processor consumer systems, based on the overheating-prone IBM PowerPC G4 processor. The original Apple tower design had a Rube Goldberg feel to it, with a host of fans straining to rid the system of heat. A noise like that emitted by a wind tunnel, generated by the power supply and fans, forced Apple to redesign the system.
This symbolized why Apple eventually abandoned PowerPC: The platform wasn't efficient with power.
Fast-forward to 2008. Game rig makers are cramming as many as four graphics chips into high-end boxes that are notable not only for performance but also for the power they consume. As a consequence, big power supply units are in vogue. Today, bragging rights extend to the units themselves: some systems boasting boutique brand names such as Cooler Master and SilverStone draw 1,200 watts--roughly three times the power requirements of game systems a few years ago.
It's an ominous trend, according to box makers. "If this trend does continue, then, yes, it will give us problems," said George Yang, an engineer at Los Angeles-based game rig maker IBuyPower. "A regular home user would have to have an electrician come in, get the outlet out, and plug in a higher breaker," Yang said. Today, some of the higher-end systems with big power supplies require a special wall power socket, according to Yang.
Other game rig makers are equally concerned. "I swore that I'd never break 1,000 (watts)," said Kelt Reeves, president of game PC maker Falcon Northwest. "Unfortunately, that's been the solution for the past several years. Bigger, bigger, bigger power supplies."
Reeves says that 1,200 watts is now essential for gaming systems based on multiple boards from Nvidia or AMD's ATI graphics unit. "With three GTX 280s or two of the R700 cards, we're recommending they go with a 1,200-watt power supply," Reeves said, referring to the newest graphics chips from Nvidia and ATI respectively.
This is just about the limit, he said. "We can't go too much more over that before--if you actually pull that (power)--you start tripping the client's household circuit breaker."
Neither Nvidia nor ATI show any signs of slowing down, according to Reeves. "Eventually these chips get so hot that their own heat becomes a barrier to performance," he said.
Nvidia admits that its chips are drawing more power than before. "If we go back about three years, our graphics card power was in the 120- to 130-watt range," said Jason Paul, product manager in charge of enthusiast GPUs (graphics processing units) at Nvidia. "The GTX 280 which we launched a couple of months back, it's around 230 watts (of) graphics card power," he said.
But Paul claims the performance per watt is the key yardstick, not raw power. "Where you see a little under 2X increase in maximum power, you've seen probably 3-times or 4-times (the) increase in the level of performance. So, overall we see a substantial improvement in performance per watt. This is the big metric we track to ensure we're delivering efficient architectures. "
Paul says Nvidia has implemented power savings techniques on its GTX 280 that keep the power down when it's not running at top performance loads. "With the GTX 280 at idle, that card runs at about 25 watts, which is one-tenth of its absolute worst-case power," he said. Nvidia also offers hybrid graphics technology that turns off all the power-sucking boards when they're not in use.
Dell XPS 730 game box uses special liquid cooling to control heat.
(Credit: Dell Computer)Moreover, Paul says that the multiboard systems are limited to a small niche at the very top of the market. "There's definitely a segment of the market that wants more and more performance. Remember, however, that this is the ultimate performance (segment)."
But game box makers ship many--if not most--of their systems to the very niche that Paul is describing. "We're all about the high end. The higher-end the graphics card is, and the more expensive, the more we sell," said Reeves.
And the trend in power supplies exemplifies how this market has changed. "The power supply used to be just silver box, and nobody gave it a second thought," he said. "(But) as graphics cards have evolved, they have forced the power supply makers to keep providing more and more power pipes--or cabling--to the graphics cards"--increasing the unit's complexity, he said.
Reeves cites GPUs, not CPUs from Intel, as the culprit. "The latest CPUs use very little wattage. If you overclock a 3GHz Intel CPU to 4GHz, you might pull 40 more watts. Whereas a graphics card, you put three of them in a system, they'll pull 800 watts running some of the higher-end games," he said.
Advanced Micro Devices announced on Monday its most powerful graphics technology to date, going after Nvidia in the rarified--and closely watched--enthusiast game segment.
This also marks the current performance pinnacle of AMD's strategy to beat Nvidia at the high end by building comparatively smaller chips and then ganging them together for better performance.
The ATI Radeon HD 4870 X2 graphics board houses two 4870 graphics processing units (GPUs) and competes with Nvidia's fastest board, based on the GTX 280. In chip-to-chip competition, Nvidia's GTX 280 generally beats a single 4870 in performance because it's bigger and faster: the Nvidia chip packs 1.4 billion transistors onto one chip, while ATI has about 950 million.
But because AMD puts two chips on one board and has improved chip-to-chip communication, the 4870 X2 is is expected to equal or exceed the Nvidia chip in many cases.
AMD has introduced a more advanced cross-GPU connection technology based on the PCIe Generation 2 standard. And the 4807 X2 can use two gigabytes of memory, compared to most high-end boards that use a maximum of one gigabyte. It also uses memory based on the new GDDR5 standard.
AMD says the 4870 X2 delivers over 3X the bandwidth of the its previous dual-GPU board, the 3870 X2
(Credit: AMD)One of the central challenges for AMD is to make sure the performance scales up efficiently when more chips are added. This is the crux of AMD's strategy: instead of building a large monolithic--albeit fast--chip as Nvidia typically does, AMD takes smaller chips and gangs them together for better performance.
To date, the results for multi-GPU performance have been problematic, typically another board will deliver only 1.5 times better performance. AMD is targeting 1.8 the performance with two chips running games in high resolution, and with four of them, about 2.5, according to earlier comments from Jon Peddie of Jon Peddie Research.
Game PC vendors expect good things. "(The 4870 X2 is) more than a match for a single Nvidia GTX 280, and depending on the title sometimes a match for two GTX 280s," said Kelt Reeves, CEO of game PC maker Falcon Northwest, responding to an email query. "Drivers are now ATI's only weak area, so the 4870 X2's performance and scaling with two 4870 X2s (QuadFire) often varies widely from title to title," he said.
In September, AMD is also expected to bring out the HD 4850 X2, a dual-chip board with slightly lower performance. The higher-end 4870 X2 is rated at 2.4 TFLOPs (or teraFLOPs a common yardstick for raw graphics chip compute power) and communicates with memory at 230GB per second, while the 4850 X2 is rated at 2.0 TFLOPs and has a memory bandwidth of 128GB/sec.
Both boards will integrate 1600 stream processors, which do parallel processing on streams of data.
The 4870 X2 is priced at $549. Nvidia preemptively responded to this by cutting the price on the GTX 280 to $499 in July.
The lower-end 4850 X2 will be available in September for $399.
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