Vendor Cards: EVGA e-GeForce 7800 GTX

Heat, Power and Noise

Heat

NVIDIA has a handy tool that measures the temperature of your card in real time, and we used this to determine the heat level generated in the different states. Again, we used the looped Battlefield 2 demos to test the power and temperature loads. As you can see in the graph, there's no difference in the temperature of the reference card and the EVGA e-GeForce 7800 GTX in normal mode, and it only went up by one degree when we overclocked it. For reference, the temperature that we achieved while the system was idle was 46 degrees.

Power

To test the power usage of the card, we measured the total watt usage of the computer at the wall outlet. We documented the power usage of our CPU in 4 different states. The first state was when the computer was idle, and with only Windows running (i.e. no other programs running). Then we plugged in our reference card and ran a performance test for the second. The two last states included the EVGA e-GeForce 7800 GTX and running the test in both normal and overclocked modes, consecutively. This way, we were able to get a general idea of how the power usage varies with the cards, and how significant an impact that it might have.

The power load that we had while the system was idle was 141 watts. So, you can see that both of the cards have a significant power draw. However, you wouldn't be able to determine precisely the power load of a card simply by subtracting the idle wattage from the overclocked wattage, since a faster GPU makes the CPU work harder to feed it data, meaning more memory accesses and an overall increase in power consumption for all components, and not just the GPU.

Noise

We didn't notice any issues with the sound level of the card. It wasn't quiet, but it wasn't as loud as some of the dust-buster solutions that we've seen in the past. The CPU fan was the dominant noise in the room, so we calculated the noise level of the card using a formula that we've employed in the past along with measurements of ambient SPL (everything off), ambient+CPU (computer on with no video) SPL, and total system SPL (everything on). We had to do this because we were unable to turn on the graphics card's fan without turning on the system.

The end result gave us an SPL of 38.4 dB, which we will compare to other cards in future articles. This number will be on par with other 7800 cards that have reference-style heat sinks; but if nothing else, we will be able to get an idea of how much noise varies for this type of heat sink.

Those fairly conscious of their computer's power usage may be reluctant to overclock the card because of the jump in power load. And if your computer case has a circulation problem or you live somewhere really hot, it may not be advisable to overclock it. But for most people, the extra heat and wattage shouldn't have that great of an impact given the performance boost.