Every time AMD or Nvidia launches a new GPU family, there’s a scramble to see whether certain features can be unlocked for other GPUs, or if cards can be updated to support higher clocks and voltages. In the old days, it was occasionally possible to buy a midrange card and unlock the additional GPU cores that had been reserved for the top-end models. Even today, there are sometimes performance gains to be had when swapping between BIOSes for different card models. Exactly how well this works and which BIOSes you can swap varies from company to company and card to card.
According to Overclock3D, some users are flashing their older RX 480s with an updated RX 580 BIOS and discovering that this can work as well. Normally, I’d be on board with this kind of change, provided that end users who try it understand the risks — but in this case, I’ve got to say I think it’s a really bad idea.
There are two major problems with flashing an RX 480 to behave like an RX 580. First and foremost, anyone with a six-pin PCI Express RX 480 is begging for trouble. AMD’s first RX 480 reference cards had a problem with drawing too much power over the PCI Express slot and not enough via the auxiliary power connectors. AMD was able to resolve this issue within days with an updated driver, but pushing the card to higher clock speeds could easily make the problem reappear. The first sign of a problem could easily be a dead monitor and the delicious scent of eau de burning PCB. This problem shouldn’t affect custom board designs from AIB vendors, but the first wave of RX 480s were based on AMD’s own reference board. If you’ve got an RX 480 with a single six-pin PCI Express connector, I wouldn’t even try this particular “tweak.”
The second problem with driving the RX 480 as hard as the RX 580 is the mammoth increase in power consumption and associated temperature increase. Our review showed the RX 580 drawing 77W more power than the RX 480 under identical test conditions, and while this gap will vary depending on board quality, cooler capability, and the RX 580’s clock speed, every review of AMD’s second-generation Polaris found the RX 580 drew significantly more power than its predecessor.While the Gigabyte RX 580 Aorus OC we reviewed is an excellent card with minimal noise and a rock-solid clock speed of 1425MHz, it’s also clearly designed for a much higher TDP than many RX 480 boards.
Most reviewers and enthusiasts tend to pay attention to GPU core temperatures above any other thermal measurement, but VRM temperatures matter a great deal as well. When Tom’s Hardware wrote an RX 480 roundup they compared GPU and VRM temperatures on a number of cards and found significant variation between them. Worse, the individual test results for GPU and VRM temperatures don’t necessarily correlate well with each other. GPUs like the Sapphire RX 480 Nitro+ keep the GPU temperature below 80C, but the VRM temperatures hit 97C.
In situations like this, pushing the VRMs even higher is nuts. They may be rated to handle it, but the PCB they’re mounted to probably isn’t, and hot spot formation could be a huge problem depending on the make and model of your GPU.
Finally, there’s the fact that depending on which BIOS you flash, you’re only getting an extra 7-12 percent performance anyway. The Gigabyte Aorus we tested had a 1425MHz clock speed, but it looks like Gigabyte pushed the envelope a little harder than anyone else. Here’s how our RX 480 (AMD reference) compared against the RX 580 in aggregate, across all games and in just DX12/Vulkan games.
When the RX 580 is, at most, 10 percent faster than the RX 480, and the risk to one’s card is substantial, I can’t recommend anyone tackle the project. A 10 percent performance gain isn’t worth spending another $ 220 – $ 260 on a new GPU.