Energy, Efficiency, And Battery Life
Our power consumption numbers shed light on the energy-saving attributes of Intel’s mobile processors, with the CrossFire-equipped M17x drawing less power than the single-card equipped X7200. The tradeoff is, of course, lower performance for the mobile parts.
There is no perfect way to compare desktop and notebook platform energy, since the power supplies can never be the same. This is particularly true with the 80 PLUS Gold-rated OCZ Z1000M power supply our desktop used, which exhibits increased efficiency as load is increased. The MALIBAL Nine X7200 uses a fanless power supply that gets somewhat warm at high loads, which should result in increased efficiency as load is decreased. It appears the desktop platform’s two low-cost GeForce GTS 450 graphics cards use about the same amount of power as the notebook’s dual high-end GTX 480M modules.
And therein is the snag for both Nvidia and power users. Nvidia’s failure is that its $800 GeForce GTX 480M is neither more efficient nor more powerful than the $130 desktop GeForce GTS 450 at the resolutions supported by most notebook panels. Power users, on the other hand, must face the fact that Intel’s Core i7-980X draws big power no matter where it’s installed, resulting in a notebook that’s 2.8” thick and reaches 43 db at full load (one meter), realistically sounds closer to 50db when you’re sitting in front of it, uses a power brick that’s larger than a red facing brick, and has a combined weight greater than that of most bowling balls.
But the woes of power users don’t end at portability and noise. Those hoping to combine the X7200’s CPU and twin graphics processors in some super-duty GPU-assisted encoding tasks should consider themselves lucky if their programs can’t take full-advantage of the GeForce GTX 480M’s capabilities. A few seconds into our attempt to run eleven threads of Prime95 and one thread of FurMark across both graphics processors simultaneously pushed at-the-wall power consumption beyond 400 W, activating the power adapter’s overload protection circuit. Performance slowed to a crawl as the system went into battery-powered mode.
The good news that followed this test was that no combination of real-world programs and games was able to create the same phenomena, with Crysis and Prime95 pulling a maximum of 372 W from the wall (below the 400+ W required to trip the automatically-resetting circuit breaker).
