Following up on this weekend's statement from AMD about a potential power issue with the reference Radeon RX 480, AMD has just sent over their previously promised update on their progress dealing with the issue.

In short, they are nearly finished preparing their updated driver, 16.7.1, which will be posted "within the next 48 hours" (which at this point is late Thursday). The new driver will offer two solutions to the power problem.

The default solution: shift some of the power load off of the PCIe Graphics (PEG) slot connector, presumably in order to bring power consumption within PCIe spec. Note that AMD doesn't say anything about reducing the total power consumption, and given option #2, it's reasonable to assume that this involves holding the power requirements as-is and shifting the load to the external 6-pin power connector. Based on earlier data this would potentially put the 6-in connector further over spec, but the vast majority of PSUs are very tolerant of this going out of spec.

The optional solution: a toggle that reduces the total power consumption of the card, presumably ensuring both the PEG slot and 6-pin power connector stay below their respective limits. Since the RX 480 is already throttling at times due to power limits, this would further hurt performance, but it's also the most standards-compliant solution (and aptly named "compatibility" mode). AMD notes that this option will have "minimal performance impact", and while we'll have to see the results in the benchmarks, it's worth noting that power consumption is cubic - that is, roughly to the 3rd power of frequency - so a small reduction in frequency can significantly reduce power consumption, as we've seen in the case of the Radeon R9 Nano.

Along with this, AMD is also touting some slight performance optimizations in this driver that they hope will offset any performance loss (though I'd note that these optimizations would have come anyhow). We'll have more on this when AMD ships their driver.

In the meantime AMD's full statement is as follows:

We promised an update today (July 5, 2016) following concerns around the Radeon™ RX 480 drawing excess current from the PCIe bus. Although we are confident that the levels of reported power draws by the Radeon RX 480 do not pose a risk of damage to motherboards or other PC components based on expected usage, we are serious about addressing this topic and allaying outstanding concerns. Towards that end, we assembled a worldwide team this past weekend to investigate and develop a driver update to improve the power draw. We’re pleased to report that this driver—Radeon Software 16.7.1—is now undergoing final testing and will be released to the public in the next 48 hours.

In this driver we’ve implemented a change to address power distribution on the Radeon RX 480 – this change will lower current drawn from the PCIe bus.

Separately, we’ve also included an option to reduce total power with minimal performance impact. Users will find this as the “compatibility” UI toggle in the Global Settings menu of Radeon Settings. This toggle is “off” by default.

Finally, we’ve implemented a collection of performance improvements for the Polaris architecture that yield performance uplifts in popular game titles of up to 3%1. These optimizations are designed to improve the performance of the Radeon RX 480, and should substantially offset the performance impact for users who choose to activate the “compatibility” toggle.

AMD is committed to delivering high quality and high performance products, and we’ll continue to provide users with more control over their product’s performance and efficiency. We appreciate all the feedback so far, and we’ll continue to bring further performance and performance/W optimizations to the Radeon RX 480.

1: Based on data running ’Total War: Warhammer’, ultra settings, 1080p resolution. Radeon Software 16.6.2 74.2FPS vs Radeon Software 16.7.1 78.3FPS; Metro Last Light, very high settings, 1080p resolution, 80.9FPS vs 82.7 FPS. Witcher 3, Ultra settings, 1440p, 31.5FPS vs 32.5, Far Cry 4, ultra settings, 1440p, 54.65FPS vs 56.38FPS, 3DMark11 Extreme, 22.8 vs 23.7  System config: Core i7-5960X, 16GB DDR4-2666MHz, Gigabyte X99-UD4, Windows 10 64-bit. Performance figures are not average, may vary from run-to-run.

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  • nevcairiel - Wednesday, July 06, 2016 - link

    That is assuming the power supply actually has the 3rd 12V connected there. Now if its part of a 6+2 setup, then it will, but if its a cheaper/older PSU and only has a pure 6-pin, maybe it doesn't?

    The key point is, even though you could use that kind of werid setup, its not following the specification, and thats just bad design for "marketing" reasons like "we can't have an 8-pin on there, it will make our card look inefficient" - guess what, it still is inefficient.
    Reply
  • bill4 - Wednesday, July 06, 2016 - link

    480 is rated at 150 watts (sometimes exceeds that a bit to be fair), 1060 which will perform similarly is rated at 120 watts. Not big difference.

    Then you come to the fact 480 has more teraflops 5.8 vs 4.4, a 256 bit bus vs 192, and comes with much more VRAM. You could probably actually argue the Nvidia card is the inneficient one.

    However efficiency is a nonsense made up thing from nvidia fanboys anyway. It doesnt matter how many watts a card uses (within reason, which all video cards under 300 watts are fine), two things matter, price, and performance. If you want to use fewer watts, go buy an IGP. It uses way less watts than an Nvidia card.
    Reply
  • bill4 - Wednesday, July 06, 2016 - link

    At least 960 Strix exceeded PCI-E by a lot (probably a lot more nvidia cards did, it was just one of only a few Nvidia cards ever tested), so Nvidia did the same thing and their fanboys made sure no stink was raised back then, it was 1000% ignored. So you cant say anything now. Reply
  • Daniel Egger - Wednesday, July 06, 2016 - link

    > A 6-pin is wired as 3x12v line, 2 ground, 1 sense pin where the 3rd 12v is not supposed to be connected.

    It's not supposed to be *used*, in many cases the connectors are actually 6+2-pin for higher flexibility. In that case you'll always have the third 12v PIN. However what goes in must come out, too and there the 3rd GND would be regrettably missed...

    Still I don't see any reason why you couldn't draw more than 75W reliably from that connector; cable lengths are reasonable short and both wires and plugs much more confidence inspiring than routing the allowed 75W through traces on the mainboard.
    Reply
  • BurntMyBacon - Wednesday, July 06, 2016 - link

    @Daniel Egger: "Still I don't see any reason why you couldn't draw more than 75W reliably from that connector; cable lengths are reasonable short and both wires and plugs much more confidence inspiring than routing the allowed 75W through traces on the mainboard."

    Given the build specifications used by most quality PSU manufacturers, you can. Bargain basement PSU manufacturers and budget OEM builds sometimes toe the line with respect to what they design their PSUs to handle.

    With respect to motherboard traces, due to the fact that current flows along the skin of a conductor, they are much more capable of carrying a load than most give them credit for. While their volume is extremely small compared to a wire, their surface area is not. Think about the burnouts you've seen. Usually you'll see charring at connectors, devices on the board, or their respective soldier joints, but how often do you see the traces get burnt. Have you ever seen traces get burnt when the connector or chip did not get burnt?
    Reply
  • BurntMyBacon - Wednesday, July 06, 2016 - link

    @KateH: "Still. Even if the connector on RX480 GPUs is rated for 250W, the 6-pin connectors on power supplies absolutely cannot be guaranteed to be."

    True. You can, however, be sure that if your connector is a 6+2pin that pigtails the last two pins of the ones next to them, then the connector will have no issue as it is already designed to carry the required currents over the six wires that will be connected.
    Reply
  • bill4 - Wednesday, July 06, 2016 - link

    awesome, i have a 6 pin like you describe with the two extra for the 8 pin on the side... Reply
  • Flunk - Wednesday, July 06, 2016 - link

    Any PSU with a 6+2 pin connector IS rated for 150W so this only applies to single 6-pin connectors. Reply
  • BlueBlazer - Wednesday, July 06, 2016 - link

    Wrong. Watch https://www.youtube.com/watch?v=plC7tOYIqBw&t=... from 54 minutes onwards. Not all of the power came from the 6-pin connnector. Toms Hardware also retested and reanalyzed the graphic card http://www.tomshardware.com/reviews/amd-radeon-rx-... and found about half of its VRM draws power from the PCI Express x16 slot instead. Reply
  • bill4 - Wednesday, July 06, 2016 - link

    what are you talking about? AMD is shifting (they only need to shift a few watts) a bit of the load from the slot to the plug. That's all. So if before under heavy load it was like 80 from slot 70 from plug, now it will be reversed and slot will be in spec. Reply

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