VGA Power Consumption
In this section, PCI-Express graphics cards are isolated for idle and loaded electrical power consumption. In our power consumption tests, Benchmark Reviews utilizes an 80-PLUS GOLD certified OCZ Z-Series Gold 850W PSU, model OCZZ850. This power supply unit has been tested to provide over 90% typical efficiency by Chroma System Solutions. To measure isolated video card power consumption, Benchmark Reviews uses the Kill-A-Watt EZ (model P4460) power meter made by P3 International. In this particular test, all power consumption results were verified with a second power meter for accuracy.
The power consumption statistics discussed in this section are absolute maximum values, and may not represent real-world power consumption created by video games or graphics applications.
A baseline measurement is taken without any video card installed on our test computer system, which is allowed to boot into Windows 7 and rest idle at the login screen before power consumption is recorded. Once the baseline reading has been taken, the graphics card is installed and the system is again booted into Windows and left idle at the login screen before taking the idle reading. Our final loaded power consumption reading is taken with the video card running a stress test using graphics test #4 on 3DMark11.
This section discusses power consumption for the XFX Radeon HD 7950 Double Dissipation graphics card, model FX-795A-TDFC, which operated at at factory-overclocked speeds. Our power consumption results are not representative of the entire Radeon HD 7950-series product family, which may feature modified designs by the various partners. Radeon HD 7950 requires two 6-pin PCI-E power connections for normal operation, and will not activate the display unless proper power has been supplied.
In our test results the XFX Radeon HD 7950 Double Dissipation graphics card consumed 18W at the lowest idle reading, and 158W under full load with fan operating at 100%. If you’re familiar with electronics, it will come as no surprise that less power consumption equals less heat output as evidenced by our thermal results below…
XFX Radeon HD 7950 Double-D Temperatures
This section reports our temperature results subjecting the video card to maximum load conditions. During each test a 20°C ambient room temperature is maintained from start to finish, as measured by digital temperature sensors located outside the computer system. GPU-Z is used to measure the temperature at idle as reported by the GPU, and also under load.
Using a modified version of FurMark’s “Torture Test” to generate maximum thermal load, peak GPU temperature is recorded in high-power 3D mode. FurMark does two things extremely well: drives the thermal output of any graphics processor much higher than any video games realistically could, and it does so with consistency every time. Furmark works great for testing the stability of a GPU as the temperature rises to the highest possible output.
The temperatures illustrated below are absolute maximum values, and do not represent real-world temperatures created by video games or graphics applications:
|Video Card||Ambient||Idle Temp||Loaded Temp||Max Noise|
|ATI Radeon HD 5850||20°C||39°C||73°C||7/10|
|NVIDIA GeForce GTX 460||20°C||26°C||65°C||4/10|
|AMD Radeon HD 6850||20°C||42°C||77°C||7/10|
|AMD Radeon HD 6870||20°C||39°C||74°C||6/10|
|ATI Radeon HD 5870||20°C||33°C||78°C||7/10|
|NVIDIA GeForce GTX 560 Ti||20°C||27°C||78°C||5/10|
|NVIDIA GeForce GTX 570||20°C||32°C||82°C||7/10|
|ATI Radeon HD 6970||20°C||35°C||81°C||6/10|
|NVIDIA GeForce GTX 580||20°C||32°C||70°C||6/10|
|NVIDIA GeForce GTX 590||20°C||33°C||77°C||6/10|
|AMD Radeon HD 6990||20°C||40°C||84°C||8/10|
|NVIDIA GeForce GTX 650 Ti BOOST||20°C||26°C||73°C||4/10|
|NVIDIA GeForce GTX 650 Ti||20°C||26°C||62°C||3/10|
|NVIDIA GeForce GTX 670||20°C||26°C||71°C||3/10|
|NVIDIA GeForce GTX 680||20°C||26°C||75°C||3/10|
|NVIDIA GeForce GTX 690||20°C||30°C||81°C||4/10|
|NVIDIA GeForce GTX 670||20°C||27°C||79°C||3/10|
|NVIDIA GeForce GTX 770||20°C||27°C||78°C||3/10|
|XFX Radeon HD 7950 Double-D||20°C||36°C||73°C||4/10|
|NVIDIA GeForce GTX 780||20°C||28°C||80°C||3/10|
No doubt the Radeon HD 7950 could benefit from improved thermal management, which is exactly why XFX incorporated their premium HydroCell vapor chamber with two Duratec IP-5X dust-free fans, and then surrounds the assembly with an aluminum “Ghost Thermal Technology” shroud. Temperatures reached 73°C after ten minutes of 100% load, which is really not much of a peak temperature by comparison. Idle temperatures were slightly higher than other video cards we’ve tested lately, but still remained at a respectable 36°C.