by Anton Shilov , Alexey Stepin, Yaroslav Lyssenko
02/01/2006 | 02:15 PM
UPDATE: Adding comments in regards ATI Radeon X1800-series lowered power consumption on the latest driver versions.
Both graphics adapters and central processing units (CPUs) used to consume so negligible amount of power ten years ago that no one cared about it: mainstream personal computers used 200W power supply units for years and we could not imagine that once we’ll need more. But the times have changed and today graphics cards alone can eat up to 120W of power, whereas dual-core processors can consume nearly 180W , therefore, we have to consider power consumption when buying or assembling new computers.
While the problem of power consumption for desktop computers is hardly as significant as some companies would like people to think, the consequences of high power requirements are growing dissipation of heat, complexity of cooling solutions and noise of fans. Modern gaming computers should feature at least four fans: one on the CPU, another on the graphics card, one to suck fresh air from outside while cooling-down the hard disk drive and one to throw the hot air out of the computer case. Contemporary high-end gaming systems – such as Alienware ALX – that include two graphics cards, also use more fans causing enormous noise.
A lot of companies, analysts and journalists recently started to talk about performance per watt ratio on modern hardware for personal computers. While the idea to limit power consumption is a good one, we have to keep in mind that energy use of flagship computers built using current silicon-based technology has been consistently rising for decades along with the performance and capabilities.
It is the speed and the amount of tasks that can be done on a computer that made people to switch from systems featuring Intel Pentium 100MHz processor and S3 Trio graphics card to PCs sporting Intel Pentium Extreme Edition chip and ATI Radeon X1900 visual processing unit. Today’s technologies allow makers of microprocessors to have more performance in mobile phone than there were in the aforementioned ten year old system, but would you like to have a computer with that speed today, even though it has power consumption of an advanced calculator? Or would you transit to a system that has similar performance as your three year old gaming computer, but has lower power requirements? Hardly.
To sum the things up: customers have been buying personal computers for years considering performance and feature-set only. There are merely a couple of reasons to start thinking about power consumption of a personal computer today: noise created by the fans and the question which power supply unit to get in case of do-it-yourself (DIY). It is inevitable that a tangibly higher-performance PC will consume more than a lower-performance one and exceptions of this general rule just manage to prove this rule.
Is power consumption a problem? Yes. Like the CO2 in the air is. But would you switch a Lamborghini for a Smart ?
Talking about power consumptions of graphic cards, we typically should consider not only power consumption alone, but other factors as well.
We believe that the list of important physical characteristics of graphics cards should include the following:
So, in overall, the question is not about power consumption only, but about plethora of specifications that can allow or not allow users to install particular graphics card into a particular system: it is not possible to install full-profile graphics card into a low-profile computer case and this limitation is not due to power consumption, but due to form-factor. Or, for example, certain boards may not suit for particular usage model: you will hardly be able to use a high-end widescreen 30” display on a graphics card that does not support dual-link DVI.
In this article we primarily measure power consumption of modern graphics cards, however, we attempt to consider the physical characteristics mentioned above in addition to some other facts that we know about the graphics cards participating in the test.
To find our how power hungry the modern graphics cards are, we used the same testing methodology as we do in our graphics cards reviews that include power consumption of graphics cards.
We utilize a special modified mainboard that has special shunts attached to PCI Express x16 power lanes as well as we attach the shunt into additional 12V power connectors that some of the graphics cards have. This way of measuring power consumptions of graphics boards was first introduced back in 2004 and has proven to be accurate since then.
Here is the configuration of the testbed we use, even though you should keep in mind that the actual hardware configuration is not really important for this particular testing.
We measured the power consumption of the card with a digital multimeter Velleman DVM850BL (0.5% measurement accuracy).To put a Peak 3D load on the card we ran the first SM 3.0 graphics test from 3DMark06 in a loop at 1600x1200 resolution and with enabled 4x FSAA and 16 anisotropic filtering (for graphics cards that did not support multi-sampling antialiasing with HDR, we did not enable it, for those who did not support Shader Model 3.0, the third game test from the 3DMark05 was used). Then we created an extremely high 2D load by launching the 2D Transparent Windows test from Futuremark PCMark05. Idle mode is power consumption of graphics card displaying Windows XP desktop.
We begin with measuring power consumption of the highest performance graphics cards available today: ATI Radeon X1900 XTX , ATI Radeon X1900 XT, Nvidia GeForce 7800 GTX 512 and overclocked Radeon X1800 XT flavour from Asustek Computer: the Extreme AX1800 XT TOP/2DHTV.
As we see, power consumption of all graphics cards is approximately similar in idle, whereas under full load in 3D the Radeon X1900 XTX is the “champ” when it comes to devouring of power. The most economical graphics card in the premium class is definitely the GeForce 7800 GTX 512 that does not even come close to the Radeon X1800- or X1900-series in terms of hunger for the energy.
The noise level created by the graphics cards we used is approximately similar: all the graphics boards can barely be heard, especially the GeForce 7800 GTX 512. If these boards are installed into a high-quality computer case, then there will be no problems with noise at all.
All the premium graphics cards are pretty long and you should check whether they are not too long for your setup. But while all of the products use dual-slot cooling systems, the one that is utilized by Asustek’s overclocked Radeon X1800 XT is the heaviest one, whereas Nvidia’s GeForce 7800 GTX 512 utilizes the lightest one.
For users of widescreen high-end liquid crystal displays (LCDs) the only choice among the premium graphics cards, are solutions by ATI Technologies: even though they consume more than the product by Nvidia, the latter does not support dual-link DVI (there are a couple of exceptions: certain graphics cards by Pny and Evga do sport a special dual-link TMDS transmitter and thus dual-link DVI), which is required for resolutions higher than 1600x1200 at 60Hz on LCD for monitors with digital connectors.
Among the high-end graphics cards we decided to measure power consumption of ATI Radeon X1800 XT 512MB , ATI Radeon X1800 XL , Nvidia GeForce 7800 GTX and Nvidia GeForce 7800 GT (we used Asus Extreme N7800GT/2DHTV ).
Power consumption of high-end graphics cards stacks according to performance.
Quite naturally, the Radeon X1800 XT 512MB consumes a lot more power than the rest of the graphics cards used here in both idle and high-performance modes. In fact, its power consumption is close to that of premium solutions, but so is its speed in games. Nvidia’s GeForce 7800 GTX consumes more power than the rest two boards, but outperforms both significantly too. The Radeon X1800 XL and the GeForce 7800 GT consume approximately similar amount of energy and their performance is also close to each other, as we know from widespread benchmark results.
The Radeon X1800 XT 512MB is not only the most power hungry high-end class product among tested today, but also the biggest and the heaviest one. It is longer than the GeForce 7800 GTX and uses dual-slot cooling system. On the other hand, it outperforms the 7800 GTX and also sports two dual-link DVI outputs unlike the rival. While the Radeon X1800 XL does not produce much noise, it is much longer than the reference GeForce 7800 GT, which may prevent it from installation into certain computer cases. On the other hand, it also sports dual-link DVI and can control its fan speed, whereas the GeForce 7800 GT sports neither of these two capabilities.
ATI has implemented dynamic clock gating technology into the Catalyst drivers, which lowered power consumption of the Radeon X1800 XT and X1800 XL compared to measurements conducted on the Catalyst 5.9 driver with Radeon X1000 support.
Graphics cards that cost from $200 to $300 are represented today by ATI Radeon X850 XT , ATI Radeon X800 XL , ATI Radeon X800 GTO (PowerColor X800 GTO VIVO ) and Nvidia GeForce 6800 GS .
The former speed daemon – the Radeon X850 XT – performs better than the rest boards, but consumes more energy compared to even more powerful products from the high-end segment. This is wny if you want to have the highest performance in this price class, you will have to admit excessive amount of power, dual-slot cooler and the absence of dual-link DVI (which is available on the Radeon X1600 XT that is slower in 3D games).
The GeForce 6800 GS consumes slightly more than the Radeon X800 XL and the Radeon X800 GTO, but the difference looks negligible while the GeForce sports some interesting capabilities, such as the Shader Model 3.0, PureVideo technology, etc.
Neither of the boards creates a lot of noise.
We used ATI Radeon X800 GT (PowerColor X800 GT ), ATI Radeon X1600 XT , Nvidia GeForce 6800 (MSI NV6800-TD128E ) and Nvidia GeForce 6600 GT (Leadtek PX6600 GT TDH ) to reveal how power hungry the modern mainstream graphics boards are.
Energy consumption of mainstream graphics cards today is definitely not high at all: it is considerably lower compared to the performance-mainstream solutions, but it is higher than that of entry-level products.
The exception is consumption of the GeForce 6600 GT which is as power hungry as the Radeon X800 GTO, but costs less and has slower performance in games . The least consuming is the GeForce 6800 product that works at very low clock-speeds, but which also cannot boast high performance. The Radeon X1600 XT does not drop its clock-speed in 2D, which is why its idle and peak 2D power consumption is not really low. But the model X1600 XT sports dual-link DVI, a capability that other graphics cards lack.
It is important to note that reference Radeon X1600 XT cannot regulate its fan speed, therefore, the product is much noisier than the rest of the boards. On the other hand, retail graphics cards may have this capability – as well as dynamic switching of clock-speeds in 2D and 3D modes – enabled.
To reveal power consumption of modern entry-level graphics cards we took ATI Radeon X1300 Pro , ATI Radeon X700 Pro (PowerColor X700 Pro), Nvidia GeForce 6600 GDDR2 (XFX GeForce 6600 GDDR2 ), S3 Graphics Chrome S27 .
The most power-hungry entry-level graphics processor is the former rival for the GeForce 6600 GT – the Radeon X700 Pro, the one that consumes the smallest amount of energy is S3’s Chrome S27.
It is interesting to point out that Nvidia’s GeForce 6600 GDDR2 consumes much less than the Radeon X1300 Pro which it usually outperforms in benchmarks . Among a few advantages that the Radeon X1300 Pro has over the GeForce GDDR2 is support for dual-link DVI, but its reference design features a pretty noisy cooler, unfortunately.
Given that consumption of such graphics cards is low enough, it fully depends on the board maker whether the graphics card creates a lot of noise or can barely be heard.
Two years ago top-of-the-range graphics cards from ATI Technologies consumed slightly less compared to the highest performing graphics boards developed by Nvidia Corp. This time the roles have changed: graphics cards based on the expensive GeForce graphics chips consume less than competing Radeon products.
In the performance-mainstream, mainstream and entry-level segments graphics cards based on ATI and Nvidia visual processing units consume about the same amount of power depending on their performance. There is nothing outstanding in those results, apart from very low power consumption of S3 Graphics’ products, which offer performance similar to other entry-level graphics cards tested.
Choosing the graphics card is a complex process which involves analysis of multiply factors, including performance in your favourite applications, anticipated speed in next-generation games and price. Power consumption is a yet another benchmark that may be important for you, or may be not. Everyone decides based on own understanding of the things.