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.

Test System
CPU:	Intel Core 2 Duo E6550 2.33 GHz (Conroe, 2x 2048 KB Cache)
Motherboard:	Gigabyte P35C-DS3R Intel P35
Memory:	2x 1024MB A.DATA DDR2 1066+ CL4
Harddisk:	WD Raptor 740ADFD 74 GB
Power Supply:	OCZ GameXStream 700W
Software:	Windows XP SP2
Drivers:	NVIDIA: 169.04 ATI: Catalyst 7.11

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

Since the Radeon HD 3870 X2 is basically two graphics cards disguised as one, the power consumption will be much higher than that of a typical single card. I did not expect such a high power consumption which rivals the 2900 XT. For the idle mode I can see some potential improvements by completely turning off the second GPU and memory when the card is running in 2D or showing a static screen. To check if your PSU will be able to handle the 3870 X2, look for 2900 XT compatibility which has similar requirements and is usually known by each PSU manufacturer.