ATI Radeon HD 4870 X2: Power Consumption, Temperature, Noise, Compatibility
It’s going to be interesting to check out the power consumption of the Radeon HD 4870 X2 just because this is the first graphics card that will surely need more than 200 watts of juice. No single graphics card has ever had such a high power draw notwithstanding what the developers said. So, we measured the power consumption of the card on 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. Practice suggests it is a heavier load for the graphics card than the tests of 3DMark Vantage. 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. Perhaps we’ll replace it with a HD video playback test which should be more interesting for the end-user. Here are the results:
So, the peak power consumption of the Radeon HD 4870 X2 is indeed as high as we predicted. It is the most voracious among all graphics cards we have ever tested. Its results in the 2D and Peak 2D modes are high, of course, yet do not differ much from those of the ordinary Radeon HD 4870. But the 3D result is terrific and far higher than everything we’ve seen before. This graphics card really needs a high-wattage power supply. It also needs an 8-pin PCI Express 2.0 power connector because it is this connector that carries the biggest load which nearly reaches the allowable maximum of 150W. Yes, you can make your Radeon HD 4870 X2 work with two 6-pin connectors but this experiment may prove disastrous because one connector will work under much higher load than what it is rated for.
Of course, the level of heat dissipation is as high as power consumption. RivaTuner doesn’t support the new card yet, but the Catalyst Control Center reported that the temperature of the GPUs on the Radeon HD 4870 X2 varied from 64°C in idle mode to 86-90°C under 3D load. The numbers seem to be acceptable but we don’t know for sure what exactly temperature the Control Center reports as the card has two GPUs and both contribute to the total amount of heat generated by the card. We know that the clock rate of the Master core is reduced to 500MHz in idle mode while the Slave core is either disabled or nearly disabled in this mode as is indicated by the power consumption tests. The warning sticker on the cooler’s casing tells you the truth, by the way. The card is indeed very hot. You can barely hold it in your hands after it has worked in 3D mode for a while.
Next we measured the amount of noise produced by the card using a Velleman DVM1326 noise-level meter. Here are the results:
Not very pleasant results these are. The card is not very noisy in 2D mode but the fan accelerates under load in order to cool the two heatsinks properly and the level of noise grows considerably, nearly reaching that of the Radeon HD 2900 XT’s cooler. Subjectively, the noise is not irritating. You can hear the sound of the airflow passing through the heatsinks rather than any noises from the fan, but the card has the same drawback as the single Radeon HD 4870. The fan speed management system is too smart. It is constantly adjusting the speed of the fan and the resulting variations in noise level may be rather irritating.
Despite the use of a PCI Express switch, the ATI Radeon HD 4870 X2 has no compatibility issues with different chipsets and mainboard whatever version (2.0, 1.0a or 1.1) of the PCI Express interface they support.