4. Power Consumption

Here, we used a plug-in power meter (the Seasonic Power Angel) to measure idle power consumption for our test system with no TV capture card plugged in. Then we made the same idle power measurement with the TV capture card plugged in to determine its idle power consumption. Finally, we measured power consumption again for each card when delivering the HQV flag sequence to the monitor through the card to provide our viewing measurement. The Hauppauge comes out as the clear winner in terms of power consumption, both at idle and at work, where the VistaView edges out the Avermedia card slightly at work; but the two are the same at idle, as shown in Chart 2.

Chart 2: Power Consumption for TV Capture Cards

Card Temperatures

We measured each capsule or chip carrier at all four corners and in the center, and took the average value for each one in degrees Centigrade, at idle and when viewing the same HQV flag sequence used to define the active viewing state for power consumption measurement. As you’d expect, there is a profound correlation between power consumption and temperatures read, but it’s subject to some interesting physical effects.

We measured the NTSC tuner because it was what was active at the time of our power testing, but during other measurements when HDTV signals were being processed, we never observed more than a two-degree variance between one tuner and the other, except for the VistaView card, where the old-fashioned and much larger metal capsule for NTSC routinely read about 6 degrees cooler than the smaller, thinner ATSC capsule. The corresponding ATSC temperature values appear in Table 2, following Chart 3.

Chart 3: TV Tuner Card Temperatures: NTSC Capsules

Table 2: ATSC Tuner Capsule Temperatures

The physical effects of volume do come into play when evaluating heat output. The dimensions of the metal capsules involved make it clear that the bigger the capsule, the lower the temperatures read. Because the AverMedia tuners are the smallest, they also manifest the highest temperatures (though there’s no correlation between size and power consumption, it’s also interesting that this card consumes the most power as well, and of course, there’s also a definite correlation between power consumption and heat output as well).