Tom’s Hardware review of the AMD Radeon RX 480 8GB, they discovered that the GPU exceeds its target 150W TDP and has a less-than-ideal power distribution between the PCIe and 6-pin power connector. This results in excessive over-current through the PCIe slot (they measured up to 90W during the stress test). The results of the tests became a big topic on Reddit, and other hardware sites also issued follow-up testing of the power issue.
AMD (which appears to be burning the midnight oil on the fix) finally issued a statement in regards to our findings.
As you know, we continuously tune our GPUs in order to maximize their performance within their given power envelopes and the speed of the memory interface, which in this case is an unprecedented 8Gbps for GDDR5. Recently, we identified select scenarios where the tuning of some RX 480 boards was not optimal. Fortunately, we can adjust the GPU’s tuning via software in order to resolve this issue. We are already testing a driver that implements a fix, and we will provide an update to the community on our progress on Tuesday (July 5, 2016).
AMD is apparently moving quickly on the issue and will provide a fix. The company will follow up with more news on later today.