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Noise and Power Consumption

We measured the level of noise produced by the graphics card’s cooler with a digital sound-level meter Velleman DVM1326 (0.1dB resolution) using A-curve weighing. At the time of our tests the level of ambient noise in our lab was 36dBA and the level of noise at a distance of 1 meter from a working testbed with a passively cooled graphics card inside was 40dBA. We got the following results:

Like the GeForce 7900 GS, the GeForce 7950 GT graphics card features a fan speed management system and thus produces little noise at work. The fan is working at its full speed only for the first couple of seconds after your turning the PC on. The system has two operation modes, a quiet 2D and a noisier 3D, but the GeForce 7950 GT remains virtually silent in every mode. The Nvidia card is preferable in this respect to the Radeon X1900 XT that comes with an old-type cooler that has been a cause of complaints from us as well as from users who want to have a quiet PC. The new cooler developed by ATI Technologies, free from the shortcomings of the older model, is only installed on Radeon X1950 XTX. 

The power consumption of the Nvidia GeForce 7950 GT was measured according to our traditional methods on the following testbed:

  • Intel Pentium 4 560 CPU (3.60GHz, 1MB L2);
  • Intel Desktop Board D925XCV mainboard;
  • PC-4300 DDR2 SDRAM (2x512MB);
  • Samsung SpinPoint SP1213C HDD (120GB Serial ATA-150, 8MB cache);
  • Microsoft Windows XP Pro SP2, DirectX 9.0c.

The mainboard in this testbed is modified: measuring shunts are connected inline into the power lines of the PCI Express x16 slot. The shunts have connectors for measuring instruments. The 2xMolex → PCI Express power adapter is also equipped with such a shunt. We perform our measurements with a Velleman DVM850BL multimeter that has a measurement accuracy of 0.5%.

To create a 3D load on the graphics card, we ran the first SM3.0/HDR test from Futuremark 3DMark06 in a loop at 1600x1200 resolution with 16x anisotropic filtering. A Peak 2D load was created by launching the 2D Transparent Windows test from Futuremark PCMark05. Here are the results:


Click to enlarge

As might have been expected, the GeForce 7950 GT takes a place between the GeForce 7900 GT and GeForce 7900 GTX. Its power draw of 61.1W in 3D mode is quite a good result for a full-featured G71-based graphics card with 512 megabytes of graphics memory on board. The Radeon X1950 Pro consumes considerably more power.

The GeForce 7950 GT resembles the GeForce 7900 GT when it comes to loading the different power lines. That’s natural as they use the same PCB design. The +3.3V line bears almost no load at all while the +12V lines have the same loads in 3D mode. As opposed to that, the GeForce 7900 GTX puts a higher load on the internal +12V line that goes through the PCI Express x16 slot.

The GeForce 7950 GT has good power consumption properties, yet its reference cooler may turn to be ineffective on it in some situations. That’s why we think the decision of some of Nvidia’s partners to equip such graphics cards with more effective coolers, justifiable.

 
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