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 i7 920 @ 3.8 GHz (Bloomfield, 8192 KB Cache) |
---|
Motherboard: | Gigabyte X58 Extreme Intel X58 Kindly supplied by Gigabyte |
---|
Memory: | 2x 1024MB OCZ DDR3 Platinum @ 1140 MHz 6-6-6-19 |
---|
Harddisk: | WD Raptor 740ADFD 74 GB |
---|
Power Supply: | BFG ES-800 800W |
---|
Software: | Windows Vista SP1 |
---|
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
Idle power consumption of our CrossFire rig is pretty high. That is because both cards reduce only their core clocks when idle, memory clock stays the same. Under load the power draw is much lower than I expected personally. The difference to a single high end card like GTX 280 or GTX 285 is fairly small. This means that any decent power supply should be able to power such a dual HD 4890 rig.
Under load the card reaches more acceptable power consumption levels which are in line with what an overclocked RV770 would consume.