AMD has been informed about the apparent abnormalities present in how the RX 480 uses power, and they’re very much committed to fixing any issues that might cause potential failure of PCs. Luckily, it seems that it’s just a simple software fix.

AMD RX 480

RX 480 power issues can be fixed easily in the drivers

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).

The issue isn’t necessarily that it draws so much power, but the allegations that it can potentially hurt motherboards in the process. The RX 480 draws more than the board TDP of 150W, both from the 6-pin connector and form the PCIe slot itself.

The PCIe slot receives power directly from the PSU itself, with traces going directly from the board to the slot, bypassing the chipeset and any other IC’s. The slot itself is rated as per the PCIe specification for up to 300W of power, far above and beyond the 75W we assume. 75W is the average power it should be consuming, though if it pulls up to 300W from the slot itself, it’s well within specification. You can read that here on page 639. Thus it’s actually fine, and shouldn’t destroy motherboards unless they’re poorly made.

Slot Power Limit Value
– In combination with the Slot Power
Limit Scale value, specifies the upper limit on power supplied by
the slot (see Section
6.9) or by other means to the adapter.
Power limit (in Watts) is calculat
d by multiplying the value in
this field by the value in the
Slot Power L
imit Scale field except
when the Slot Power Limit Scale field equals 00b (1.0x) and Slot
Power Limit Value exceeds EFh, the following alternative
encodings are used:
F0h = 250 W Slot Power Limit
F1h = 275 W Slot Power Limit
F2h = 300 W Slot Power Limit
F3h to FFh = Reserved for Slot Power Limit values above
300 W
This register must be implemented
if the Slot Implemented bit is
Writes to this register also cause the Port to send the
Set_Slot_Power_Limit Message.