Power Consumption, Temperature, Noise, Overclocking
We reported to you about the power consumption of the Radeon HD 4870 in an earlier review but didn’t publish the detailed data about the load on each of the power lines. Now we want to offer you these data as measured on our 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:
As you can see, there is a good reason for the card to have two power connectors because their combined load is somewhat higher than the maximum permissible load for one 6-pin PCIe 1.0 connector, which is 75 watts. The numbers explain the necessity of an advanced dual-slot cooler. The Radeon HD 4870 is far from economical, even though it consumes less power than Nvidia’s newest solutions, especially GeForce GTX 280. The Radeon HD 4870 doesn’t have any special requirements to the PSU. Any high-quality 400-450W power supply will do. Of course, you need a higher-wattage PSU if you build a graphics subsystem out of two such graphics cards. We guess a 600W PSU should be enough. The only prerequisite is that the PSU had four graphics card connectors. Otherwise you’ll have to use adapters.
The reference Radeon HD 4870 is not cool at work. The GPU temperature is as high as 78°C when idle and 89-90°C under load. This may indicate some flaws in the cooler design, particularly the use of aluminum instead of copper, which make the Radeon HD 4870 rather noisy as you’ll see shortly. The samples of the card we dealt with were prone to overheat and reboot the driver. Hopefully, off-the-shelf samples will be free from this defect.
We measured the amount of noise produced by the card with a Velleman DVM1326 noise-level meter. We got the following results:
The Radeon HD 4870 is rather quiet in 2D mode, at least its noise is not irritating. The fan management system behaves oddly under load, speeding the fan up for a few seconds and then slowing it down again. This variation in noise level isn’t agreeable. Hopefully, the fan control algorithm will be corrected in the off-the-shelf cards because it is uncomfortable to use a Radeon HD 4870 when it sounds like this.
There are no compatibility issues. Like the junior model, the Radeon HD 4870 starts up on any mainboard irrespective of the version of PCI Express the latter supports.