Power Consumption

Cooling modern video cards is becoming more and more difficult, especially when users are asking for quiet cooling solutions. That's why the engineers are now paying much more attention to power consumption of new video card designs.


In order to characterize a video card's power consumption, the whole system's mains power draw was measured. This means that these numbers include CPU, Memory, HDD, Video card and PSU inefficiency.

The three result values are as following:

• Idle: Windows sitting at the desktop (1024x768 32-bit) all windows closed, drivers installed.
• Average: 3DMark03 Nature at 1280x1024, 6xAA, 16xAF. This results in the highest power consumption. Average of all readings (two per second) while the test was rendering (no title screen).
• Peak: 3DMark03 Nature at 1280x1024, 6xAA, 16xAF. This results in the highest power consumption. Highest single reading

In the following graph we measured the card only power consumption of the HD 4830 Green versus the HD 4830 reference design. As you can see the HD 4830 Green consumes slightly more power in idle, but about 10W less under load.
What this test also shows is that the card exceeds the PCI-Express slot power limit of 75W in this test. According to the PCI-Express specification the maximum slot power for a full height x16 card is 75W. So technically the card is out of spec, does it matter? Not at all. Such a small increase won't be a problem for any component in your computer. I would even say that overclocking this card is a perfectly safe thing to do. As you can see on the overclocking page of this review we did get a healthy overclock out of the card without running into any problems.




Power limits as defined by the PCI-Express specification.

For completeness here are the results of our full system power consumption testing (we will switch to the card only method in future reviews):