Power Consumption of Contemporary Graphics Cards
During our test session we obtained the following results:
It would be incorrect to call “Windows 7 desktop” mode idle mode, because even if the user is not doing anything, the graphics adapter does display the OS interface on the screen. Any work with 2 D applications, such as office tasks, for instance, can be included into the same category. This is where the new Advanced Micro Devices solutions have no equals. Even the top single-processor solution in the family, ATI Radeon HD 5870, consumes only a little over 15 W. the only exception to this rule is Radeon HD 5970, but it would be silly to assume that those who decide to go with this two-headed monster would ever care about energy-efficiency. Moreover, even this solution in “desktop” mode consumes less that Radeon HD 4890, which is indeed pretty uneconomical unlike other Radeon HD 4000 solutions.
As for Nvidia solutions, the best ones would be the products using new 40 nm graphics processors – GeForce GT 240, 220 and 210. In terms of energy-efficiency, they can compete successfully against their AMD rivals. However, the readings taken off the products on G200 leave much to be desired: not the most optimal production process for the cores of this complexity definitely has its standing here. Luckily, it looks like GeForce GTX 295 can disable one of the cores in this mode, which makes it more energy-appealing than Radeon HD 5970. GeForce 9 solutions also don’t star in this test, which is quite logical. Overall, if you are mostly using your computer in office and other 2D applications, then graphics products from Advanced Micro Devices would be your best bet. You just have to remember that according to some sources, Radeon HD 5000 series still experiences some problems with 2D acceleration in Windows 7 that is why for AutoCAD and similar type of tasks Nvidia solutions could be a better choice.
During HD video playback the laurels go to ATI Radeon HD 5000, which offers decent energy-efficiency and fully-fledged HDMI 1.3a support including flawless transfer of high-definition multi-channel sound formats over HDMI. Nvidia solutions on 55 nm and 65 nm cores are not just uneconomical in this mode, but also do not fully support hardware VC-1 format decoding moving some of the load to the CPU. Luckily, GeForce GT 240, 220 and 210 are free from this issue, but they still do not support protected audio path, so you will have to forget about Dolby TrueHD or DTS-HD Master Audio. You can read more about the multimedia capabilities of inexpensive AMD and Nvidia solutions in our latest article called ATI Radeon HD 5670, Radeon HD 5570 and Radeon HD 5450: A Multimedia Ideal?.
Radeon HD 5000 is also ahead in games. Even the top solution from this lineup, the dual-processor Radeon HD 5970, consumes considerably less than Nvidia GeForce GTX 295. Even 40 nm production process doesn’t really help Nvidia that much here: GeForce GT 240 GDDR5 is way less energy-efficient than its direct competitor - Radeon HD 5670. And of course, do not forget that all ATI Radeon HD 5000 solutions support DirectX 11, which current Nvidia solutions do not have by definition. In other words, the choice of gaming fans is obvious here.
However, we have to say that Radeon HD 5830 may in the end turn out a less appealing buy than Radeon HD 4890. Although the latter doesn’t support DirectX 11 and consumes considerably more power, it also runs faster in a number of cases. Moreover, Radeon HD 5830 turns out even less energy-efficient in games than the faster Radeon HD 5850, which results from its higher chip speed of 800 MHz against 725 MHz.
The results discussed in this part of our review are interesting mostly from the theoretical prospective. We would warn you against repeating our tests in OCCT: GPU, because we have record of quite a few cases when not only the PSU safety would kick in, but also when graphics cards would fail because their electric circuitry couldn’t bear the load created by this synthetic benchmark. In fact, the results of OCCT: GPU test do not reveal anything new to us: the today’s most energy-efficient solutions are still the ones from Radeon HD 5000 family, although the difference between Radeon HD 5870 and GeForce GTX 285 is really minimal in this case.
Overall, the situation is pretty clear: the best choice for those who care about energy-efficiency of their computer system would be one of Radeon HD 5000 solutions except the dual-processor Radeon HD 5970. In our opinion, the most optimal model offering the best combination of power consumption and high 3D performance is Radeon HD 5850. Nvidia GeForce GTX 275 would be a good alternative to it. Although it consumes considerably more power in games, it may still become a more preferable choice in a number of situations, namely in applications that depend a lot on the quality of 2D acceleration or in CUDA apps. As for non-gaming solutions, Radeon HD 5670 and 5570 look pretty good here. I would call them the best choice for a multimedia platform for high definition video and audio formats. It has every chance to become extremely economical among other things.