Functional Benchmarking: Noise And Heat
Nobody wants a video card that sounds like a vacuum cleaner under load, so we measured how these cards performed acoustically. To our surprise, they were a little too quiet to measure in the usual way by reading the noise at the back of the case. So to get meaningful readings, we had to open the case and measure the noise within an inch of each card. This tells us that both PowerColor and Sapphire have reasonably quiet cooling solutions on their 4830s. Here are the results:
As you can see in our benchmark, PowerColor’s card seemed to make use of variable fan speeds while Sapphire’s card tended to use only a single-fan speed in testing. While the chart shows some variance, the real-world difference was negligible as neither card was really audible over our Cooler Master Cosmos-S case in regular conditions.
Our final benchmark is heat. We know the cooling systems are quiet, but let’s see how effective they are:
At first glance, the Sapphire card looks like a superior solution at idle. But keep in mind that the Sapphire 4830 idled at only 160 MHz on the core and 250 MHz on the memory, while PowerColor’s idled at 453 MHz on the core and 750 MHz on the memory. This accounts for the large variance in idle-speed temperatures.
Once the cards are put under a load, we can see a more reasonable temperature difference. Overclocked to 690 MHz, the temperature of both the PowerColor and Sapphire 4830 cards hovered from a mid to high 60 degrees Celsius, with the Sapphire card showing a slight advantage. This isn’t that significant when you realize that we don’t need to worry about these graphics processors until their temperatures reach at least 90 degrees Celsius.
Even overclocked to 765 MHz on the core, the PowerColor 4830 still kept the temperature under 80 degrees Celsius. This is an excellent load temperature for such a high overclock, showing that the RV770LE graphics processor really is designed to handle a much higher clock speed than the stock 575 MHz.