Power Consumption, Noise, Temperature
Notwithstanding the modest growth of the GPU and memory frequencies, we decided to measure the power draw of the Toxic HD 4850 to see if the factory overclocking had any effect on the card’s electrical characteristics. We used a special testbed configured like follows:
- AMD Athlon 64 FX-55 CPU (2.6GHz)
- EPoX EP9-NPA+ SLI mainboard (Nvidia nForce4 SLI)
- PC3200 SDRAM (2x512MB, 200MHz)
- Western Digital Raptor WD360ADFD HDD (36GB, SATA-150, 16MB buffer)
- Chieftec ATX-410-212 PSU (410W)
- Microsoft Windows Vista Ultimate 32-bit
- Futuremark PCMark05 Build 1.2.0
- Futuremark 3DMark06 Build 1.1.0
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. Here are the results:
The results are even lower than we expected. The Sapphire consumes a mere 5 watts more than the reference Radeon HD 4850 and doesn’t differ much from the latter in terms of temperature. The load on the 6-pin PCI Express connector is increased, but the 1.5W violation of the permissible limit shouldn’t be a problem.
Zalman’s cooler helped achieve wonderful results. The GPU temperature was 44-47°C in idle mode and no more than 65°C under load. For comparison, the reference cooler from ATI keeps the CPU temperature at 62°C and 86°C, respectively. That’s a superb result, proving the wise choice of the developer.
Next we measured the card’s noise with a digital sound-level meter Velleman DVM1326.
The results agree with what we could hear with our ears: the card is silent under ordinary conditions. You can only hear it in a fan-less PC system but the Toxic HD 4850 is not meant for them. And if the system case is closed, the card’s noise will be barely perceptible.
So, the Sapphire Toxic HD 4850 proved to have superb noise and thermal characteristics. Let’s now check it out in games to see if the factory overclocking has an effect on its performance.