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.


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

Sapphire's HD 4730 is a juice hungry beast. Its power consumption is comparable to the HD 4870 - which is over 50% faster! Due to the choice of GDDR5 memory, the memory clock can't be reduced in idle because it causes flickering. So the memory clock is always running at 900 MHz. For the core frequency Sapphire chose to go with an idle clock of 600 MHz which is way too high in my opinion. Something in the neighbourhood of 300 MHz would have helped to reduce the idle power consumption.

The GPU voltage in idle is 1.287V and 1.330V under load, which is quite high. The HD 4770 runs at around 1.0V, the HD 4850 reference around 1.15V, the HD 4870 at 1.3V. So in order to achieve the high default clock speed of 750 MHz on a large percentage of ASICs my guess is that either AMD or Sapphire bumped up the voltage, resulting in higher power consumption.