Power Consumption, Temperature, Overclockability and Noise
Information about the power consumption of the GeForce GTX 285 is highly important, so we performed our usual test on a specially configured testbed:
- Intel Pentium 4 560 CPU (3.6GHz, LGA775)
- DFI LANParty UT ICFX3200-T2R/G mainboard (ATI CrossFire Xpress 3200 chipset)
- PC2-5300 SDRAM (2x512MB, 667MHz)
- Western Digital Raptor WD360ADFD HDD (36GB)
- Chieftec ATX-410-212 PSU (410W)
- Microsoft Windows Vista Ultimate SP1 32-bit
- Futuremark PCMark05 Build 1.2.0
- Futuremark 3DMark06 Build 1.1.0
Following our standard method, the 3D load was created by means of the first SM3.0/HDR test from 3DMark06 running in a loop at 1600x1200 with 4x FSAA and 16x AF. The Peak 2D mode was emulated by means of the 2D Transparent Windows test from PCMark05. This test is important as it simulates the user’s working with application windows whereas Windows Vista’s Aero interface uses 3D features.
According to our test, the new card has a peak power consumption of 150W at the reference frequencies and 161W at the pre-overclocked frequencies. This is very good in comparison with the slower Radeon HD 4870, let alone the Radeon HD 4850 X2 which needs over 200W. The information about the distribution of load among the individual power lines suggests that there is indeed no need for 8-pin connectors: the load on the external +12V lines is below 75W even with the pre-overclocked card from EVGA. Like every GeForce GTX 200 series solution, the EVGA GeForce GTX 285 SSC lowers the GPU clock rates to 300/600MHz and the memory frequency to 100 (200) MHz when idle to save power in 2D mode.
The EVGA is not cool because it has a simplified cooler. Its GPU temperature is lower in idle mode than that of the 65nm GeForce GTX 280 but as high as that of the GeForce GTX 295 under load.
On the other hand, even 86°C is far from critical for a modern GPU. Moreover, the high temperature is made up for by the rather comfortable noise parameters of the card.
The only noise the EVGA card produces is the hiss of the airflow as it is passing through the heatsink and being exhausted through the card’s mounting bracket. Never in our long tests did the card increase its fan speed. Thus, the rather high temperatures in 3D mode are due to the relaxed settings of the fan control system. Generally speaking, it is far more comfortable to be near a system that has an EVGA GeForce GTX 285 SSC inside than near one that has a Radeon HD 4870 X2 or a Sapphire Radeon HD 4850 X2.
Our overclocking attempt was a failure. We managed to increase the GPU clock rates from the default 702/1584MHz to 720/1624MHz and also lift the memory frequency up to 1400 (2800) MHz but the card eventually proved to be unstable.
We then dropped the CPU frequency to 710MHz, but the card got unstable after a while, again. Therefore we had to roll back to the default clock rates and give up the idea of benchmarking the EVGA card at overclocked frequencies. We were not surprised much at our failure. The G200 is too complex after all. Even on 55nm tech process this core seems to have a frequency limit at about 700/1600MHz unless you resort to extreme overclocking methods like increasing the GPU voltage. We could not check this out because EVGA’s tool for controlling this parameter only supports cards with a Volterra VT1165 controller whereas the voltage regulator of the GeForce GTX 285 is based on an Intersil ISL6327.