Power Consumption, Overclockability, Temperature, Noise

As we know from our earlier tests, the Radeon HD 5670 has a power draw of 30 watts in 3D applications. Anyway, we measured the power consumption of our Axle Radeon HD 5670 to check out how voracious the RV830 chip is when overclocked. We used the same testbed configured as follows:

• Intel Core 2 Quad Q6600 CPU (3GHz, 1333 MHz FSB x 9, LGA775)
• DFI LANParty UT ICFX3200-T2R/G mainboard (ATI CrossFire Xpress 3200 chipset)
• PC2-1066 SDRAM (2x2 GB, 1066MHz)
• Enermax Liberty ELT620AWT PSU (620W)
• Microsoft Windows 7 Ultimate 7 64-bit
• CyberLink PowerDVD 9 Ultra/"Serenity" BD (1080p VC-1, 20 Mbit)
• Crysis Warhead
• OCCT Perestroika 3.1.0

The new testbed for measuring electric characteristics of graphics cards uses a card designed by one of our engineers, Oleg Artamonov, and described in his article called PC Power Consumption: How Many Watts Do We Need?. As usual, we used the following benchmarks to load the graphics accelerators:

• CyberLink PowerDVD 9: FullScreen, hardware acceleration enabled
• Crysis Warhead: 1600x1200, FSAA 4x, DirectX 10/Enthusiast, "frost" map
• OCCT Perestroika GPU: 1600x1200, FullScreen, Shader Complexity 8

Except for the maximum load simulation with OCCT, we measured power consumption in each mode for 60 seconds. We limit the run time of OCCT: GPU to 10 seconds to avoid overloading the graphics card's power circuitry.

ATI Catalyst Control Center does not allow to raise the core and memory clock rates above 850 and 1050 (4200) MHz, respectively. Therefore we used MSI Afterburner, changing the value of the EnableUnofficialOverclocking parameter to 1 in the file Afterburner.cfg. After that the card could be overclocked to GPU and memory frequencies of 900 MHz and 1120 (4480) MHz, respectively.

It was stable and passed the full cycle of our tests at these clock rates. And here is how much power the overclocked Axle Radeon HD 5670 1GB GDDR5 needs:

The difference is obvious. The Radeon HD 5670 doubles its power draw in overclocked mode and consumes as much as the Radeon HD 5750 although its performance can hardly be as high as the latter’s. The difference in specs is not in favor of the Axle card, but we will see everything in the next section of the review.

The cooling system did a good job despite the hot weather. It easily kept the GPU of our Axle Radeon HD 5670 as cool as 56-60°C. The maximum temperature was 64°C in the overclocked mode. These are good results compared to those of the GeForce GT 240, though.

The cooling system deployed on the Axle Radeon HD 5670 is very similar to the one we saw on the Gigabyte GV-R567OC-1GI and produces about the same amount of noise. Both cards are louder than the reference sample from AMD in terms of decibels but the latter is not that agreeable to the ear. In fact, the large fans of the Axle Radeon HD 5670 and Gigabyte GV-R567OC-1GI produce but a soft hissing sound of the air passing through the heatsink. The fans of both cards do not change their speed at high load. We would call them silent despite the formally higher level of noise in decibels compared to the reference card from AMD.

Now we want to proceed to the theoretical part of our review to see what an overclocked Radeon HD 5670 can do in today’s games.