Gigabyte GV-N66256DP Fanless Graphics Card

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TEST RESULTS

Ambient conditions at the time of testing were 22°C, and 121V / 60 Hz.

Initial testing was done with the integrated graphics on the system motherboard to establish baseline levels for system power and CPU temperature. Unfortunately, neither RTHDRIBL nor 3DMark05 would run on the integrated graphics chip, so only the only load on the system was CPUBurn. Proper stress on the integrated graphics might raise the results by another 5~10W, but the impact on the rest of the system temperatures would probably be minimal.

VGA Test Bed: Baseline Results (no external VGA card)
System State	System Fan Voltage	System Power Consumption (AC)	CPU Temperature
Idle	12V	56W	29°C
CPUBurn	12V	119W	46°C
CPUBurn	9V	120W	49°C
CPUBurn	7V	120W	50°C
CPUBurn	5V	120W	53°C

Once the baseline testing was complete, the Gigabyte GV-N66256DP was installed, and the real testing began.

VGA Test: Gigabyte GV-N66256DP
System State	System Fan Voltage	System Power Consumption (AC)	CPU Temperature
Idle	12V	71W	30°C
CPUBurn & RTHDRIBL	12V	159W	46°C
CPUBurn Only	5V	138W	54°C
CPUBurn & RTHDRIBL	5V	162W	52°C
3DMark05	5V	155W (peak) 140~150W (typical)	–

CPU temperature changed very little compared to the original baseline results and power consumption changed very little with the speed of the system fan. For this reason, only a few of the more interesting results are shown in the table above; the rest are redundant.

Even with the system fan running at its slowest speed (5 volts), no signs of visual artifacts were ever present, so the card passed our test. The card has since been installed in a permanent system where it has been running World of Warcraft and Lineage II: The Chaotic Chronicle flawlessly for the last two weeks.

An estimate of the power consumption of the graphics card can be obtained by comparing the total system power with and without the card. The following procedure was used to derive the estimates in the table below:

1. The system AC power consumption was measured at various loads, with and without the Gigabyte card.
2. We used efficiency test results from our Antec Neo HE 430 review to estimate the approximate DC output power being delivered at the various AC input power measured.
3. The power consumption of the graphics card at idle was assumed to be the difference in power demand between the two systems when both were running CPUBurn.
4. The power consumption of the graphics card under load was assumed to be the difference between the system with the card running CPUBurn and RTHDRIBL simultaneously, and the baseline system running CPUBurn only. This ensured that any load on the CPU from RTHDRIBL did not skew the results, since the CPU was running at full load in both cases.

Video Card Power Consumption: Gigabyte GV-N66256DP
GPU State	Estimated DC Power Consumption	Total increase in System Power (AC)
Idle	15W	+18W
RTHDRIBL	32W	+39W

As a final practical test of the card's capabilities, we ran five consecutive iterations of the 3DMark05 benchmark. Power consumption averaged about 10~15 watts lower than the full CPUBurn + RTHDRIBL test. This is a much more realistic test of the kind of load the card will be under in actual use; gaming is a dynamic load, and very few games place the system under the kind of continuous load that CPUBurn and RTHDRIBL achieve. As with the RTHDRIBL test, no visual artifacts were detected.

CONCLUSIONS

The GV-N66256DP is still a worthwhile investment as a no-noise upgrade to an older AGP-based system. Our efforts at overheating the card all went for naught, and it performed flawlessly even with the most minimal airflow cooling in our test bed. The Zalman-designed heatsinks appear to work perfectly well.

This achievement is all the more impressive because the amount of power consumed by the card is not trivial. 32 watts may be relatively little for a graphics card these days, but keep in mind that a 32 watt CPU would need careful airflow design and large heatsink to be cooled passively. The fact that Gigabyte managed to overcome the cooling limitations of the ATX form factor is impressive.

Many thanks to Gigabyte Technology for the GV-N66256DP sample.

SPCR Articles of Related Interest:
Chaintech AA6800GT + Arctic Cooling NV Silencer 5
Arctic Cooling ATI Silencer 2 VGA Cooler
Arctic Cooling VGA Silencer
Zalman ZM-80 VGA Heatpipe Cooler

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