NVIDIA and ATI HDCP Compatible Graphics Cards Roundup

Heat Levels

Heat and noise levels are related to power requirements, but we still wanted to see what kind of heat levels we would see with each of these cards during operation. We tested this in much the same way as in our power consumption tests. For the heat tests, we used ATI Tool, specifically the "scan for artifacts" function, which causes the GPU to continually draw a fuzzy cube in order to stress the card. After five minutes of stress testing, we then take the heat reading of the die through the software. We also take heat readings while the system is idle for reference.





We found that NVIDIA did a little better in general at dissipating heat, with the exception of the silent XFX GeForce 7950 GT which saw the highest heat levels of the bunch, including even the 8800 GTX. This makes sense considering the card has no fan and instead uses a large passive heat sink to cool it down. The silent Gigabyte 7600 GS also saw high heat levels for the same reason. The larger-than-usual heat sink on the MSI NX7600 GT (non HDMI) seemed to do a good job at cooling the GPU, as this was one of our coolest running cards. Heat levels are something to consider if you plan on overclocking your card, if you are in a hot environment, or if you have poor case circulation. Under these conditions, active cooling solutions are generally preferrable.

Noise

Of more importance for these particular cards is the amount of noise they generate. Excess noise from GPU fans can be a hindrance when putting together a system that is as quiet running as possible for a home theater setup. To test noise we took the dB level of the room with the system off to determine the ambient noise level; this was 38.1 dB. We then took dB readings of the cards while running a stress test (the same as in our heat level tests) to determine how much noise the cards made during operation. These are our results.




The ASUS EN7600 GT is particularly noisy. When the fan kicks in, it makes a much louder whine than it does when the system is idle. The Sapphire X1950 XTX was also fairly noisy once it got hot and the fan kicked in, but it seems to only speed up in short intervals. The EVGA 7900 GS KO also saw a high noise level under stress. We found that the EVGA and BFG 7950 GX2s both ran pretty quietly considering their performance, which is a nice feature of these cards. Of course the silent Gigabyte 7600 GS as well as the XFX 7950 GT HDCP would be good choices if you were looking for a card with zero noise, but it's especially nice having completely silent operation with a higher performance card like the 7950 GT. Because the noise level of these cards was 0Db, they were not included in the graphs, but the noise level of the CPU will still be a factor for HTPC users. Note that you will almost certainly want a case that provides sufficient cooling if you choose to run either of these fanless cards.