Bios modding Guide for AMD GPUs

In this post of CFE, i’m gonna be explaining how to bios mod amd gpus and how it affects the hashrate. So here it goes …….

Well lets start with some stats, stock AMD 580 8GB gpu does 24MH/s or close to that out of the box, BUT after a BIOS mod, they do anywhere from 30MH/s to 32MH/s, so is a BIOS mod needed, well its up to you to decide.

Linked below is the tool most people use to mod a BIOS, its known as Polaris BIOS Editor, and since we can’t find PBE on the interwebs, we decided to upload our copy of it.


  1. for windows computers
  2. File transfer program like WinSCP, FileZilla, or MobaXTerm for windows computers

Video Tutorial

Written Tutorial


Using a windows computer we will save the GPU bios on ethos, transfer it to windows, modify the bios file, transfer it back to ethos, and then flash the GPU’s with the modified bios file.


On the windows computer open Putty or MobaXterm and SSH into the ethos miner, Run the command

sudo atiflash -s 0 original-RX580-xxx-xxx-xxx-Micron.rom

where 580 is the model of the GPU, xxx-xxx-xxx is the bios ID, and Mircon is the memory, all of this can be found in the stats command run from ethos. If the memory is Unknown then the chances are its Micron.

Next use the file transfer program of your choice to copy the file off of EthOS and put it on your windows computer.

Now you can use Polaris Bios Editor 1.6.7, load the original bios file and use the “One Click Timing” button to update the memory timing straps on your vbios. Save the file changing the file name from original to modified and this step is done.

Almost there, use your file transfer program to copy the modified file back to the EthOS miner.

Finally, on the SSH terminal again run the command

sudo atiflash -p 0 modified-RX580-xxx-xxx-xxx-Micron.rom

You should see the GPU being flashed at this point. Once done either flash another GPU or reboot the miner with


Thats all, you are done flashing the vbios on EthOS.

We recommend using the One Click Timing button and not other edits because the EthOS config file can handle the majority of the GPU’s vbios needs. By making vbios mods hard set in the vbios some will stack on EthOS settings and others are not permanently useful. The more that is altered in them the more often they need updating.

Best practices when setting up a remote config

Setting up a config file is pretty easy and straight forward, but most of the times, people stick to inefficient ways of doing it.

The real trick to a good and efficient mining operation is a good setup and a good and easy to edit config file, so that is where we are focus our attention here.

What most people will do is use the some random global values they found on youtube or some forum, but the thing that most people don’t realize is that those values will not ALWAYS work for everyone,¬† many need higher values and many will need lower ones. So searching for random values is not that good, instead what one should do is test different values on a bunch of GPUs so that a baseline can be created, and in case of most farms they get their GPUs in bulk hence the performance is quite similar among the GPUs so its well worth it. As for the global values, one should use the values based on the bios name instead of a static global value.

One method we use is the use of rig specific and GPU specific values for fine tuning because here at CFE we strive for max performance even though it takes us hours if not days to achieve it. GPU specific values are the best as they give the best hashrate and shares, but it is tedious, and once you get to a certain level, using global defaults is the best.