AMD’s FX processor line-up was supposedly designed with efficiency in mind, according to AMD. We're putting this claim to the test, assessing the Bulldozer architecture at a number of different clock rates and comparing the results to Intel's CPUs.
The FX-8150 can only reliably achieve higher clock rates when we apply more voltage to it. The result is better performance in the application benchmarks, but with the consequence of higher power consumption as frequency goes up. At idle, the differences are small, and range from 73 to 81 watts, which think is reasonable for an "eight-core" CPU.
Loaded up with benchmark applications, the differences in power consumption are much more pronounced. Up to about 4.0 GHz, the wattage increases only moderately. But from 4.5 GHz upwards, the power consumption rises dramatically, and any notion of power efficiency has to be abandoned.
- Overclocking And Undervolting AMD's FX Family
- The Bulldozer Platform: Using FX-8150 To Test
- Water Cooling Versus Two Air Coolers
- Clock Frequency: 3.6 GHz, Multiplier: 18x, CPU Voltage: 1.332 V
- Clock Frequency: 3.8 GHz, Multiplier: 19x, CPU Voltage: 1.352 V
- Clock Frequency: 4.0 GHz, Multiplier: 20x, CPU Voltage: 1.38 V
- Clock Frequency: 4.5 GHz, Multiplier: 22.5x, CPU Voltage: 1.428 V
- Clock Frequency: 4.6 GHz, Multiplier: 23x, CPU Voltage: 1.5 V
- Clock Frequency: 3.6 GHz, Multiplier: 18x, CPU Voltage: 1.116 V
- Test System, Benchmarks, And Settings
- Benchmark Results: Archiving And Professional Applications
- Benchmark Results: Matlab
- Benchmark Results: Audio/Video
- Benchmark Results: Energy Consumption (Idle/Load)
- Single-Thread Efficiency Test
- Multi-Threaded Efficiency Test
- Combined Efficiency Test Results
- Efficiency Score And Power Diagram
- Overclocking And Efficiency Are Like Oil And Water With Bulldozer