NVIDIA GeForce 8800 Ultra review - Page 6

Les températures de la carte graphique

Since we tested a lot of series 8 cards we'll now simply start adding temperature results into a graphical overview compared with other manufacturers.

Let's have a look a look at thermal performance. We measured at a room temperature of 22 Degrees C.

For the chart, temperature is in Degrees Celsius: lower = better

Despite that huge cooler the 8800 Ultra still will get quite hot. It makes sense, faster clocks often equal a slightly higher voltage scheme. And not only that, we have nearly 700 million transistors on this product at work, that's generating heat. So at system idle / desktop work expect temperatures of a degree or 60 Celcius. At fill peak utilization temperatures will rise towards 80 degrees C. True that's a lot but as stated the product can manage it really well. The beauty of the cooler design is that this heat is pushed outwards of your PC as exhaust at the connector side.

Le pouvoir "The Power"

We'll now show you some tests we have done on overall power consumption of the PC. Looking at it from a performance versus wattage point of view, the power consumption is really not bad. Our test system is a Core 2 Duo X6800 Extreme Processor, the nForce 680i SLI mainboard, a passive water-cooling solution on the CPU. Furthermor we find a DVD-ROM and WD Raptor drive in this system. Have a look.

The methodology is simple: we look at the peak wattage during a 3DMark05 session with hefty IQ settings to verify power consumption. It's a good load test as both GPU and CPU are utilized really hard here. Please do understand that you are not looking at the power consumption of the graphics card, but the consumption of the entire PC.

We had a total system wattage peak at roughly 370 Watts for the 8800 Ultra card, which is quite a lot. We simply place a wattage meter in-between the PSU and power socket. It's not the most objective way to test as you have to consider PSU efficiency as well, but it's the best thing we can do though.

So despite NVIDIA's claims its not more less power hungry but slightly more, well a lot of variables can effect this. Well okay so 5 Watts. whatever right ?

In my view the GeForce 8800 Ultra requires you to have a 500 Watt power supply unit at minimum if you use it in a high-end system. Also recommended is 35 AMPs on the 12 volts rails for stable power distribution.

You'll also notice that the GTX & ultra use two 6-pin power connectors so I'd like to strongly advise a PSU with dual 12-volts rails here. 

Why does the GeForce 8800 Ultra have two 6-pin power connectors? Well, the PCI Express spec allows for 75W from the edge connector plus 75W from each external 6-pin power connector. The GeForce 8800 GTX requires two 6-pin power connectors to deliver the full power requirements of the board while adhering to the PCI Express edge connector and 6-pin connector specification.

If you have dough to spend and opt the guru path of righteousness by doubling up towards two cards in your system -> SLI, then you should end up with a 700 Watt or better PSU with a 45 AMPs 12 Volts rail.

There are some good PSU's out there, again have a look at our many PSU reviews as we have loads of recommended PSU's for you to check out in there. What would happen if your PSU can't cope with the load?:

• bad 3D performance
• crashing games
• spontaneous reset or imminent shutdown of the PC
• freezes during gameplay
• PSU overload can cause it to break down

Noise Levels coming from the graphics card

When graphics cards produce a lot of heat, usually that heat needs to be transported away from the hot core as fast as possible. Often you'll see massive active fan solutions that can indeed get rid of the heat, yet all the fans these days make the PC a noisy son of a gun. I'm doing a little try out today with noise monitoring, so basically the test we do is extremely subjective. We bought a certified dBA meter and will start measuring how many dBA originate from the PC. Why is this subjective you ask? Well, there is always noise in the background, from the streets, from the HD, PSU fan etc etc, so this is by a mile or two not a precise measurement. You could only achieve objective measurement in a sound test chamber.

The human hearing system has different sensitivities at different frequencies. This means that the perception of noise is not at all equal at every frequency. Noise with significant measured levels (in dB) at high or low frequencies will not be as annoying as it would be when its energy is concentrated in the middle frequencies. In other words, the measured noise levels in dB will not reflect the actual human perception of the loudness of the noise. That's why we measure the dBa level. A specific circuit is added to the sound level meter to correct its reading in regard to this concept. This reading is the noise level in dBA. The letter A is added to indicate the correction that was made in the measurement. Frequencies below 1kHz and above 6kHz are attenuated, where as frequencies between 1kHz and 6kHz are amplified by the A weighting.

We startup a benchmark and leave it running for a while. The fan rotational speed remains constant. We take the dBA meter, move away 75 CM and then aim the device at the active fan on the graphics card.

We measure roughly 44 dBa on the PC with 8800 Ultra graphics card.

So overall these are really acceptable sound levels coming from the PC. Again, this is a very subjective test and that dBa level includes all noise in the environment.