AMD Radeon HD 6870 Graphics Card

Graphics Cards
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POWER

The power consumption of an add-on video card can be estimated by comparing the total system power draw with and without the card installed. Our results were derived thus:

1. Power consumption of the graphics card at idle - When CPUBurn is run on a system, the video card is not stressed at all and stays idle. This is true whether the video card is integrated or an add-on PCIe 16X device. Hence, when the power consumption of the base system under CPUBurn is subtracted from the power consumption of the same test with the graphics card installed, we obtain the increase in idle power of the add-on card over the integrated graphics chip.

2. Power consumption of the graphics card under load - The power draw of the system is measured with the add-on video card, with CPUBurn and FurMark running simultaneously. Then the power of the baseline system (with integrated graphics) running just CPUBurn is subtracted. The difference is the load power of the add-on card. Any load on the CPU from FurMark should not skew the results, since the CPU was running at full load in both systems.

Both results are scaled by the efficiency of the power supply (tested here) to obtain a final estimate of the DC power consumption.

Note: the actual power of the add-on card cannot be derived using this method because the integrated graphics may draw some power even when not in use. If we assume our old test system with GMA 950 graphics used 1~2W, we estimate that the integrated HD 4200 graphics chip in our new setup uses 2W more than that, based on tests conducted using a low-end reference card. However, the relative difference between the cards should be accurate.

Estimated Power Consumption (DC)
Card
Idle
Load
ATI HD 4870 1GB
55W
147W
HIS HD 4890 Turbo 1GB
57W
153W
HIS HD 5870 Turbo 1GB
22W
216W
AMD HD 6870 1GB
18W
163W

By our estimates, the HD 6870 uses 18W when idle, a touch better than the 19W claimed, and a savings of 4W compared to the factory-overclocked HIS HD 5870 Turbo. This may be because of the core/memory speeds, which according to GPU-Z, are only 100/80 MHz when idle. On load the 6870 uses 53W less than the HIS HD 5870 Turbo, a substantial improvement that should make cooling the 6870 a much easier task.

VIDEO PLAYBACK

Video Playback Comparison
Test State
AMD Radeon HD 6870
HIS Radeon HD 5870 Turbo
Avg.
CPU
Avg. Power*
Avg.
CPU
Avg. Power*
Rush Hour
(1080p H.264)
10%
+40W
12%
+46W
Coral Reef
(WMV-HD)
12%
+41W
11%
+46W
Spaceship
(1080p x264)
16%
+45W
15%
+51W
*compared to idle (AC)

Though UVD 3 adds a few features to the 6870 in terms of video playback, the H.264 and VC-1 acceleration remains the same as it was in UVD 2. As a result, the average CPU usage of our test system was similar during H.264/VC-1 playback whether we used the 6870 or the older 5870. The 6870 gave us a small power savings but this is likely due to its lower idle power.

MP3 SOUND RECORDINGS

These recordings were made with a high resolution, lab quality, digital recording system inside SPCR's own 11 dBA ambient anechoic chamber, then converted to LAME 128kbps encoded MP3s. We've listened long and hard to ensure there is no audible degradation from the original WAV files to these MP3s. They represent a quick snapshot of what we heard during the review.

These recordings are intended to give you an idea of how the product sounds in actual use — one meter is a reasonable typical distance between a computer or computer component and your ear. The recording contains stretches of ambient noise that you can use to judge the relative loudness of the subject. Be aware that very quiet subjects may not be audible — if we couldn't hear it from one meter, chances are we couldn't record it either!

The recording starts with 5~10 seconds of room ambiance, followed by 5~10 seconds of the VGA test system without a video card installed, and then the actual product's noise at various levels. For the most realistic results, set the volume so that the starting ambient level is just barely audible, then don't change the volume setting again.



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