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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  • Geranium - Wednesday, July 06, 2016 - link

    I wonder how much power those 6-pin less GTX 950 consume? Reply
  • AS118 - Wednesday, July 06, 2016 - link

    Don't be a fanboy, the 480's are sold out everywhere online. Which is good for ALL gamers. Hopefully AMD gains enough marketshare to where NVidia will stop being as much of a near-monopoly. Reply
  • joeycagle - Wednesday, July 06, 2016 - link

    It appears to be sold out everywhere. I came across a pre-order on Amazon, however, that said it wouldn't be available until July 13. It was one of the few items that wasn't at a rip off price (actually at MSRP rather than the 300-some odd dollars they're being sold for mostly there) and so I went ahead and pre-ordered. That was yesterday. Today, I found out it was actually shipped and it will be here tomorrow.

    So if you want one, go to Amazon for a pre-order. Just be sure you're not overpaying. You may find the next day it is actually being shipped right then.
    Reply
  • bill4 - Wednesday, July 06, 2016 - link

    someone better tell their stock thats up like 300% the past year. Reply
  • GTRagnarok - Wednesday, July 06, 2016 - link

    #1 sounds good to me. The 6pin connector is pretty underspec'd, isn't it? There's plenty of power headroom. Reply
  • T1beriu - Wednesday, July 06, 2016 - link

    The 6pin on the RX480 is actually routed and used as an 8pin. It can handle 250W.

    The 6 pin feeds the vcore and the PCIE bus feeds the memory.
    Reply
  • KateH - Wednesday, July 06, 2016 - link

    Could u clarify what u mean by "routed and used as an 8pin"? I've looked at bare PCB shots for RX480 and I see a 6-pin connector with 6 leads soldered to 6 thru-holes on the board. The limiting factor for power delivery in this case is that each wire going from the PSU to the GPU has a limit to the current it can safely carry, as does each pin inside the connectors on the PSU cable and GPU.

    I guess I could see a 6-pin connector handling 250W @12v, but that would be roughly 20A per pin which would have to mean 16 or 14-gauge wires from the PSU to GPU and a lot of trust put into the power connectors on the GPU and PSU...
    Reply
  • KateH - Wednesday, July 06, 2016 - link

    I did my math wrong on those amperage ratings. 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. Reply
  • blahsaysblah - 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. An eight pin uses that 3rd 12v(same location) and adds a 2nd sense pin and a 3rd ground. The RX 480, because its power controller can detect no power condition, does not need the sense pin. So they actually wired their port to have the 3rd 12V line active, and turned the sense pin into ground(which is what it is on PS side). You can safely use a 6-pin there and pull "150W" 8-pin power as long as power supply has enough overall rating for it. Technically, ATX12V version 2.2(~2006, 2.4 is 2013) required the pins to switch to HCS/High Current Series, so if your motherboard/PS follow that, they can drive 9A per wire (assuming they dont cheap out on wire). It was 6A per wire before. There are actually 11A HCS Plus pins that maybe are used by high end motherboards and power supplies. Side note, ATX 20pin has one 12v and 24pin has two 12v wires. Whole point of +4 was to safely get more power to PCI-E bus via motherboard. Reply
  • blahsaysblah - Wednesday, July 06, 2016 - link

    EDIT: For example, i had no idea about all this before RX 480. Back than, i bough wire matching what came with my PS when i created my own set of custom power cables. I bought 18AWG tin clad copper 16 strands of 30 AWG wire which said its rated for 300v/7A. So even using my lower 7A rating, that 6-pin(assuming RX 480 port isnt weak link) can pull 3x12Vx7A or 252W. However, technically, same applies to power supply, the actual internal traces and contacts technically only have to support 150W or 50W/4A per wire. Just because the pins are rated for 9A, nothing mentions a power requirement other than 75W/150W. Anyway, there is not technical reason the 6-pin cannot safely provide 150W 8-pin power. The 3rd 12v line is there in specs, just not used. And the missing 3rd ground is more of the liability(which they fixed because they dont need sense pin). Reply

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