Power Consumption Results
Measurement Methodology & Graphical Illustration
Taking into account the lessons learned from our follow-up measurements of AMD's Radeon RX 480 and your feedback, we made some fundamental changes to the way we measure power consumption.
Our measurement intervals are now twice as long. There's also a hardware-based low-pass filter and software-based variable filter in place (the latter is a feature of the software used to analyze data; it's designed to evaluate the plausibility of very short load peaks and valleys). The resulting curves are a lot smoother than the old ones; we hope you derive more value from them as a result.
You'll find more information about our power consumption test methodology in The Math Behind GPU Power Consumption And PSUs.
You'll find a larger number of bar graphs, and higher-resolution versions of our power consumption charts that you can expand by clicking on them. We restructured our topic sections, added more comparison bar graphs, and, finally, added different scenarios to our measurements. In addition to power consumption, we also examine current to determine whether the graphics card stays within all of its relevant specifications. Our test equipment doesn't change, though:
| Power Consumption Measurement | |
|---|---|
| Test Method | Contact-free DC Measurement at PCIe Slot (Using a Riser Card) Contact-free DC Measurement at External Auxiliary Power Supply Cable Direct Voltage Measurement at Power Supply |
| Test Equipment | 2 x Rohde & Schwarz HMO 3054, 500 MHz Digital Multi-Channel Oscilloscope with Storage Function 4 x Rohde & Schwarz HZO50 Current Probe (1mA to 30A, 100 kHz, DC) 4 x Rohde & Schwarz HZ355 (10:1 Probes, 500 MHz) 1 x Rohde & Schwarz HMC 8012 Digital Multimeter with Storage Function |
Power Consumption at Different Loads
Similar to our Radeon RX 470 coverage, we're adding several games to our measurement suite, though the familiar Metro: Last Light benchmark also turns out to be the Radeon RX 460's biggest challenge. It’s followed closely by Doom, which generates numbers that are almost as high. However, there’s a difference of less than 3W between Ashes of the Singularity and Metro: Last Light. This means that Asus’ graphics card is consistently running close to or at its limit.
The Strix RX 460's almost 90W result is a lot higher than what we expected based on AMD’s pre-launch PR. Then again, this is Asus' interpretation of the RX 460, which benefits from factory overclocking in our performance charts, but pays the price when we measure power. We're pretty sure there will be other RX 460s that do away with the power connector altogether. Ultimately, you're the one who has to decide if performance headroom or an efficient card without a power connector is more important.
The gray bar represents power consumption based on those load peaks that made it through our filters to the smoother curve. That bar doesn't have any practical significance since the peaks we measured are too brief for them to matter (even if the shortest-duration ones were already filtered out by this point).
Power Connector Load Distribution
So, how’s the load distributed across the power rails during a realistic gaming load and a stress test? We aren't including the motherboard's 3.3V rail in this discussion, because it's barely used (up to 1W, but usually less than that).
Load on the two 12V rails (the motherboard slot connector and six-pin power connector) is balanced beautifully. There’s lots of room left on them both. Even additional overclocking efforts will never push Asus' Strix RX 460 beyond the limits set in its specifications.
Here are the corresponding graphs for gaming and our stress test. Click on them for a larger version.
The PCI-SIG’s specifications only apply to current, meaning power consumption results on their own don't tell the whole story. Our readings put the motherboard slot just over 4A. Given a ceiling of 5.5A, this is most certainly on the safe side with lots of room to spare.
Of course, there are larger graphs for the current measurements as well.
Power Consumption Comparison with Other Graphics Cards
Finally, we’d like to know how the Strix RX 460 stacks up against other graphics cards. We're using the peak power consumption numbers for this comparison because they're what the previous results consisted of.
Gaming power consumption is much lower compared to older graphics cards. The same can't be said for Blu-ray playback and multi-monitor setups, though. Asus' Strix RX 460 lags way behind its competition in those disciplines.
AMD tells us that there's a fix for the high power consumption readings at idle and under partial loads. Unfortunately, it didn’t make it into the latest driver, which we used for these tests.
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