Power Consumption, Temperature, Noise and Overclocking

The new GeForce GTX 295 has a new power circuit so we retested its power consumption to see how it changed after the changes in design. We used a special testbed configured as follows:

• Intel Pentium 4 560 CPU (3.6 GHz, LGA775)
• DFI LANParty UT ICFX3200-T2R/G mainboard (ATI CrossFire Xpress 3200 chipset)
• PC2-5300 SDRAM (2 x 512 MB, 667 MHz)
• Western Digital Raptor WD360ADFD HDD (36 GB)
• Chieftec ATX-410-212 PSU (410 W)
• Microsoft Windows Vista Ultimate SP1 32-bit
• Futuremark PCMark05 Build 1.2.0
• Futuremark 3DMark06 Build 1.1.0

Following our standard procedure, the 3D load was created by the first SM3.0/HDR test from 3DMark06 running in a loop at 1600x1200 with forced 4x FSAA and 16x AF. The 2D load was emulated by the 2D Transparent Windows test from PCMark05. The graphics card worked at its default GPU and memory frequencies.

We’ve got the following results:

Click to enlarge

The new GeForce GTX 295 is more economical than the older version: the difference is 11.3W under load. Perhaps this is the benefit of Nvidia’s EPWM technology implemented in the PWM regulators of GPU voltage. The load is distributed among the power lines in a somewhat different manner, but the 8-pin connector still has the heaviest load of all. The peak power draw of 203W is a good result for a solution with two GPUs each consisting of 1.5 billion transistors. We guess AMD should think about power efficiency of its solutions as the Radeon HD 4870 X2 is less economical and delivers lower performance. And we doubt that a hypothetical Radeon HD 4890 X2 can beat the new GeForce GTX 295.

The new card is also impressive in terms of temperature. Its GPUs were never hotter than 74-78°C despite the summer heat!

The idle mode numbers are very good, too. The older version of GeForce GTX 295 does not even come close to that, notwithstanding its sophisticated cooler. Interestingly, the temperature of the GPU located near the mounting bracket is always 2-4°C lower than that of the other GPU because the hot air from the latter stays within the system case. Anyway, the new GeForce GTX 295 is the best in its class in terms of temperature.

When it comes to noisiness, we got the following results measuring the card’s noise level (at an ambient noise of 43dBA):

The new GeForce GTX 295 is as noisy as the older one in ordinary mode but its noise spectrum is more agreeable to the ear. When the card has been working long under load, its noise grows up to the level of the Radeon HD 4870 X2 which is considered one of the loudest graphics cards. However, the noise spectrum is less annoying. It is not the rattling of the fan bearing together with resonating plastic as with the Radeon HD 4870 X2, but the hiss of the airflow passing through the heatsinks. We guess this noise is not irritating and can be put up with. This is the price you pay for high cooling efficiency and good overclockability.

As for overclockability, we managed to increase the card’s frequencies from its default 576/1242MHz to 675/1455MHz and it was perfectly stable though all of our tests. Although its memory chips have a rated frequency of 1000 (2000) MHz, we overclocked them to an impressive 1250 (2500) MHz. Of course, such a good frequency growth should produce a nice performance boost. Therefore we benchmarked our Inno3D GeForce GTX 295 Platinum at the overclocked frequencies, too.