One way to undervolt R9 300 series cards by BIOS mod

[bobben2]

Inspired by the excellent work recently by Eliovp (Thread on undervolting Nano cards),
I set fore to find out if I could successfully undervolt my R9 380X and 390 cards by
modding the cards bios.  
The short answer is Yes in both cases.
THe background I wanted to save some Watts while mining Eth.  I had successfully undervolted
my 280X cards earlier.

You can do the same!
If you are willing to mess with the BIOS of your card to save some Watts, then please
read on, but consider the risk.  You can brick your card, i.e. your computer wont start
after BIOS flash.  You will need to understand the risk and know how to recover a
bricked card.  Also, consider that you will void any warranty on your card when
you flash the BIOS.  I will not be held responsible.
If you are still reading, then I assume you are fine with the above warning.

Here is a brief how to undervolt the 390.

You need the following software:   ATIflash and HawaiiBiosReader.
You can download the latest ATIflash from TechPowerUp.  Version 2.71 works fine.
Download HawaiiBiosReader from GitHub.  Google it to find it.
You should already be familiar with how the ATIflash tool works. I wont go into
the detail here. Instead you can read Eliovp's thread. He describes it in detail.

TBH I didn't use the HawaiiBiosreader myself. I ended up creating my own utility to
alter the voltage tables myself.  But the effect is the same and this description assumes HawaiiBiosReader.

1. Get the stock bios from the card:  atiflash -s 0 card390_orig.ROM
This cmd will read the BIOS from card in slot 0 and store it in the file card390_orig.rom
Backup this file so you can restore the original BIOS to the card later.

2. Run HawaiiBiosReader.  Open file card390_orig.ROM.  
You will need to modify the voltage values in 6 tables. Note that the voltage
values you choose will have to be the same in all the 6 tables.  And for each row,
the next value will have to be same as previous or increase.

There are two tables under the Powerplay tab and 4 tables under the Limit tables tab.
The values you want to change are in the vol column in all the 6 tables.
You may leave the value in the first row in all tables as is.
The other values are pointers into the BIOS voltage table. Those values depend on
the chip quality.  Dont worry about that.
You will replace these pointers with real voltage values (in mV).
At this point you will have to take great care!
The voltage values you are about to enter will have to be values divisible by 6.25
(socalled SVI2). For example, you should not enter 1111, but 1112 is near enough, so it is fine.
Here are the values I finally loaded into the tables for my Sapphire R9 390 Nitro
and that I found is working great at stock frequencies 1040/1500.
1000
1000
1050
1050
1100
1100
1100
1106
You may want to start off using higher values.  For example, try 1150 in the DPM7 row.
Then gradually work your way down.  
Do not change anything else other that the voltage values.  When done, save to a file,
for example card390_1150.rom

3. Flash the card:   atiflash -p 0 card390_1150.rom
This assumes the card you want to modify is in slot 0.
You might want to try the -f switch if atiflash complains.
Sit back and wait for the flash to complete. Then reboot your computer and
test.   You may want to run your miner for a good few hours before you can conclude
on stability and whether you can undervolt further.

For the R9 380X card the procedure is similar, but again I ended up writing my own
utility to modify the BIOS.  I studied the code that was written by Hedzin.

At stock frequencies I was able to reduce power consumption of the 380X by 40Watts
and the 390 by ~48Watts.  Specific power consumption:  380X  ~140W, 390: ~167W
380X is hashing at 20MH/s (7Ws/Mh), 390 is hashing at 27MH/s (6.18Ws/Mh)


NB! You may not be able to undervolt further in Afterburner, Trixx, etc.  
Depending on your card you may not be able to overclock the core after
you have done undervolting.

Happy mining!

EDIT: I just checked the temperature of my single 390 mining at 1040/1500.
Sensor 0: Temerature - 58.00 C
Fan speed: 38%
Ambient temperature: 23 C.
I tribute the low temperature to the excellent tri-fan cooler of the Sapphire card, and of course the lower voltage.

EDIT2:
For those interested in Hawaii bios editing in general you can read this very comprehensive writeup
by gupsterg.  I find that guide very valuable.

http://www.overclock.net/t/1561372/hawaii-bios-editing-290-290x-295x2-390-390x


EDIT 20160816:
For thos of you who happen to have the Sapphire 380X or 390 Nitro cards  I here provide som ROMs
that you can try on your own cards.  If you are running with stock BIOS then these will save you 40 Watts per card easy.
You should be familiar with atiflash and aware of the risk involved in
flashing the BIOS of your card. I bear no responsiblity for any damage.

Sapphire 380X Nitro 1081mV ROM:

https://www.dropbox.com/s/fmgva4twgukbrl1/sapp380x_1081.rom?dl=0


Sapphire 380X Nitro 1100mV ROM:

https://www.dropbox.com/s/irt9dup5mwuxqbj/sapp380x_1100.rom?dl=0


Sapphire 390 Nitro 1100mV ROM:

https://www.dropbox.com/s/gw0lhozg4hskz2a/sapp390_1100.rom?dl=0


Sapphire 390 Nitro 1106mV ROM:

https://www.dropbox.com/s/3yybo5kxcet7mba/sapp390_1106.rom?dl=0

[ldw-com]

Hey Bobben2!

Thank you for your detailed explanation.

What you wrote will definitely work!

I do it a little bit different.

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

What you did, as said before, will definitely work, but is in a way a little more intensive, because the dpm values won't be set automatic, the controller will use what is set.

In some cases this could go wrong, for example, the card will need a specific amount of voltage, but the dpm value associated to that clock won't be able to give enough.

Regarding power, in this case it will use less power in comparison from what i do

I'm glad you worked things out!

As said before, i'm still working on it, my target is to achieve the same results as the Stilt did with his released hawaii roms from a few years ago.

Will keep you posted in this thread as well!

Greetings!

[Siskaver]

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

I saw your XFX mod. You used 800 instead of 900 in the original BIOS. I tried your mod, but it does not change the voltage of the core at all.

Are you still working on that?

[Next BillG]

OP, thanks for sharing. You used
1000
1000
1050
1050
1100
1100
1100
1106

For frequency from 800 to 1040. For the lower frequency, are the voltage too high?

How do you change the memory voltage?

[Next BillG]

The second table is the mem freq table. Should that have the same voltage value as the GPU Freq Table?

[bobben2]

Hey Bobben2!

Thank you for your detailed explanation.

What you wrote will definitely work!

I do it a little bit different.

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

What you did, as said before, will definitely work, but is in a way a little more intensive, because the dpm values won't be set automatic, the controller will use what is set.

In some cases this could go wrong, for example, the card will need a specific amount of voltage, but the dpm value associated to that clock won't be able to give enough.

Regarding power, in this case it will use less power in comparison from what i do

I'm glad you worked things out!

As said before, i'm still working on it, my target is to achieve the same results as the Stilt did with his released hawaii roms from a few years ago.

Will keep you posted in this thread as well!

Greetings!

Hi ldw-com.
Yes, you are right.  Probably the "correct" way of doing it is to offset the values in the BIOS instead of overwriting the pointer values..  However, I could not mind to find the correct entries in the BIOS.  At least, what I have works ok at stock frequency.

[bobben2]

OP, thanks for sharing. You used
1000
1000
1050
1050
1100
1100
1100
1106

For frequency from 800 to 1040. For the lower frequency, are the voltage too high?

How do you change the memory voltage?

Hi Next BillG
The first voltage value in the stock BIOS was 1000 mV.  Therefore, I started with 1000.  I've seen ASUS BIOS start at 900mV.  I am not concerned about it.  It is the DPM7 value that will matter to miners.
Idk how to change the memry voltage.  However, I am able to change the voltage of the mem controller.
For my Sapphire card I changed it from 1050 to 1025 mV.

[bobben2]

The second table is the mem freq table. Should that have the same voltage value as the GPU Freq Table?

Yes.  All 6 tables should have identical values.

[Boathouse]

OP, thanks for sharing. You used
1000
1000
1050
1050
1100
1100
1100
1106

For frequency from 800 to 1040. For the lower frequency, are the voltage too high?

How do you change the memory voltage?

Hi Next BillG
The first voltage value in the stock BIOS was 1000 mV.  Therefore, I started with 1000.  I've seen ASUS BIOS start at 900mV.  I am not concerned about it.  It is the DPM7 value that will matter to miners.
Idk how to change the memry voltage.  However, I am able to change the voltage of the mem controller.
For my Sapphire card I changed it from 1050 to 1025 mV.

How do you change the memory controller voltage? Are they the same as the memory voltage? How much power saving did you get?

[bobben2]

OP, thanks for sharing. You used
1000
1000
1050
1050
1100
1100
1100
1106

For frequency from 800 to 1040. For the lower frequency, are the voltage too high?

How do you change the memory voltage?

Hi Next BillG
The first voltage value in the stock BIOS was 1000 mV.  Therefore, I started with 1000.  I've seen ASUS BIOS start at 900mV.  I am not concerned about it.  It is the DPM7 value that will matter to miners.
Idk how to change the memry voltage.  However, I am able to change the voltage of the mem controller.
For my Sapphire card I changed it from 1050 to 1025 mV.

How do you change the memory controller voltage? Are they the same as the memory voltage? How much power saving did you get?

You can change the memcontroller voltage in HawaiiBiosReader.  If you look in the PowerPlay tab.
Table VDDCI states.  The rightmost value is the controller voltage.
If it is already at 1000 (mV), then I dont think it can go much lower.
I dont think there is much to save lowering this value, but I might be wrong.

[Boathouse]

OP, thanks for sharing. You used
1000
1000
1050
1050
1100
1100
1100
1106

For frequency from 800 to 1040. For the lower frequency, are the voltage too high?

How do you change the memory voltage?

Hi Next BillG
The first voltage value in the stock BIOS was 1000 mV.  Therefore, I started with 1000.  I've seen ASUS BIOS start at 900mV.  I am not concerned about it.  It is the DPM7 value that will matter to miners.
Idk how to change the memry voltage.  However, I am able to change the voltage of the mem controller.
For my Sapphire card I changed it from 1050 to 1025 mV.

How do you change the memory controller voltage? Are they the same as the memory voltage? How much power saving did you get?

You can change the memcontroller voltage in HawaiiBiosReader.  If you look in the PowerPlay tab.
Table VDDCI states.  The rightmost value is the controller voltage.
If it is already at 1000 (mV), then I dont think it can go much lower.
I dont think there is much to save lowering this value, but I might be wrong.

Is that the same as aux voltage? I changed that with -100mV in the MSI afterburner. It save about 1W power.

[bobben2]

OP, thanks for sharing. You used
1000
1000
1050
1050
1100
1100
1100
1106

For frequency from 800 to 1040. For the lower frequency, are the voltage too high?

How do you change the memory voltage?

Hi Next BillG
The first voltage value in the stock BIOS was 1000 mV.  Therefore, I started with 1000.  I've seen ASUS BIOS start at 900mV.  I am not concerned about it.  It is the DPM7 value that will matter to miners.
Idk how to change the memry voltage.  However, I am able to change the voltage of the mem controller.
For my Sapphire card I changed it from 1050 to 1025 mV.

How do you change the memory controller voltage? Are they the same as the memory voltage? How much power saving did you get?

You can change the memcontroller voltage in HawaiiBiosReader.  If you look in the PowerPlay tab.
Table VDDCI states.  The rightmost value is the controller voltage.
If it is already at 1000 (mV), then I dont think it can go much lower.
I dont think there is much to save lowering this value, but I might be wrong.

Is that the same as aux voltage? I changed that with -100mV in the MSI afterburner. It save about 1W power.

Yes,  I believe that is the one.  The mem controller will be sitting mostly idle when mining Eth.  If you try mining DCR
then its a different story.

[Next BillG]

But the memory controller load is usually over 90% if I set the frequency to be 1250 MHz. I think Etehreum uses a lot of memory access.

[bobben2]

Hey Bobben2!

Thank you for your detailed explanation.

What you wrote will definitely work!

I do it a little bit different.

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

What you did, as said before, will definitely work, but is in a way a little more intensive, because the dpm values won't be set automatic, the controller will use what is set.

In some cases this could go wrong, for example, the card will need a specific amount of voltage, but the dpm value associated to that clock won't be able to give enough.

Regarding power, in this case it will use less power in comparison from what i do

I'm glad you worked things out!

As said before, i'm still working on it, my target is to achieve the same results as the Stilt did with his released hawaii roms from a few years ago.

Will keep you posted in this thread as well!

Greetings!

Hi ldw-com
Are you there?
I am trying to locate the actual voltage table so I can offset the values as per your suggestion.
The evv pointers are supposed to point into the actual voltage table (evv value XOR 0xFFFF I believe
will give the offset into the powertable in the bios where the voltage value is stored.  Or--?)
I am doubting this logic for 2 reasons:
byte offset whereas the actual voltage values need at least 16-bit storage.
The actual values I find by using the above logic are "all over the place".
Suggestions?

[Eliovp]

Hey Bobben2!

Thank you for your detailed explanation.

What you wrote will definitely work!

I do it a little bit different.

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

What you did, as said before, will definitely work, but is in a way a little more intensive, because the dpm values won't be set automatic, the controller will use what is set.

In some cases this could go wrong, for example, the card will need a specific amount of voltage, but the dpm value associated to that clock won't be able to give enough.

Regarding power, in this case it will use less power in comparison from what i do

I'm glad you worked things out!

As said before, i'm still working on it, my target is to achieve the same results as the Stilt did with his released hawaii roms from a few years ago.

Will keep you posted in this thread as well!

Greetings!

Hi ldw-com
Are you there?
I am trying to locate the actual voltage table so I can offset the values as per your suggestion.
The evv pointers are supposed to point into the actual voltage table (evv value XOR 0xFFFF I believe
will give the offset into the powertable in the bios where the voltage value is stored.  Or--?)
I am doubting this logic for 2 reasons:
byte offset whereas the actual voltage values need at least 16-bit storage.
The actual values I find by using the above logic are "all over the place".
Suggestions?

Hey Bobben,

ldw-com is me when i'm at work (just so you know)

if you open your rom with atomicbiosreader you'll get a .txt output, just scroll down check under data tables for "VoltageObjectInfo", the offset is there on the left.

Open your hex editor and go to that offset. If it's there, it'll be like so 8D 00 "YOUR VALUE HERE" 00 for memory voltage it'll be like so: 8E 00 "YOUR VALUE HERE" 00.

To change that value to -100mV you'll need to add F0 where i typed "YOUR VALUE HERE" :p ..  If you need extra explanation on how to calculate that, just ask :p

In some cases those values do not exist and you'll need to add them yourself.
In other cases it just isn't possible to edit memory voltage (like my 390 nitro's) <-- check my Nano thread "last post"


Greetings!

[Next BillG]

Hey Bobben2!

Thank you for your detailed explanation.

What you wrote will definitely work!

I do it a little bit different.

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

What you did, as said before, will definitely work, but is in a way a little more intensive, because the dpm values won't be set automatic, the controller will use what is set.

In some cases this could go wrong, for example, the card will need a specific amount of voltage, but the dpm value associated to that clock won't be able to give enough.

Regarding power, in this case it will use less power in comparison from what i do

I'm glad you worked things out!

As said before, i'm still working on it, my target is to achieve the same results as the Stilt did with his released hawaii roms from a few years ago.

Will keep you posted in this thread as well!

Greetings!

Hi ldw-com
Are you there?
I am trying to locate the actual voltage table so I can offset the values as per your suggestion.
The evv pointers are supposed to point into the actual voltage table (evv value XOR 0xFFFF I believe
will give the offset into the powertable in the bios where the voltage value is stored.  Or--?)
I am doubting this logic for 2 reasons:
byte offset whereas the actual voltage values need at least 16-bit storage.
The actual values I find by using the above logic are "all over the place".
Suggestions?

Hey Bobben,

ldw-com is me when i'm at work (just so you know)

if you open your rom with atomicbiosreader you'll get a .txt output, just scroll down check under data tables for "VoltageObjectInfo", the offset is there on the left.

Open your hex editor and go to that offset. If it's there, it'll be like so 8D 00 "YOUR VALUE HERE" 00 for memory voltage it'll be like so: 8E 00 "YOUR VALUE HERE" 00.

To change that value to -100mV you'll need to add F0 where i typed "YOUR VALUE HERE" :p ..  If you need extra explanation on how to calculate that, just ask :p

In some cases those values do not exist and you'll need to add them yourself.
In other cases it just isn't possible to edit memory voltage (like my 390 nitro's) <-- check my Nano thread "last post"


Greetings!

I saw you also have a XFX R9 390 card. When your mod is ready, can you share with us the mod rom please?

[ldw-com]

i'll see what i can do 

[bobben2]

Hey Bobben2!

Thank you for your detailed explanation.

What you wrote will definitely work!

I do it a little bit different.

I modify the rom in a hex editor and change the voltage entirely.

In other words, i do not change the dpm tables, i just lower the entire voltage by -100mV (for example) so that the controller itself will automatically give the voltage that is needed.
In this case, a specific clock won't give you issues as the controller will adjust voltage for what is needed.

What you did, as said before, will definitely work, but is in a way a little more intensive, because the dpm values won't be set automatic, the controller will use what is set.

In some cases this could go wrong, for example, the card will need a specific amount of voltage, but the dpm value associated to that clock won't be able to give enough.

Regarding power, in this case it will use less power in comparison from what i do

I'm glad you worked things out!

As said before, i'm still working on it, my target is to achieve the same results as the Stilt did with his released hawaii roms from a few years ago.

Will keep you posted in this thread as well!

Greetings!

Hi ldw-com
Are you there?
I am trying to locate the actual voltage table so I can offset the values as per your suggestion.
The evv pointers are supposed to point into the actual voltage table (evv value XOR 0xFFFF I believe
will give the offset into the powertable in the bios where the voltage value is stored.  Or--?)
I am doubting this logic for 2 reasons:
byte offset whereas the actual voltage values need at least 16-bit storage.
The actual values I find by using the above logic are "all over the place".
Suggestions?

Hey Bobben,

ldw-com is me when i'm at work (just so you know)

if you open your rom with atomicbiosreader you'll get a .txt output, just scroll down check under data tables for "VoltageObjectInfo", the offset is there on the left.

Open your hex editor and go to that offset. If it's there, it'll be like so 8D 00 "YOUR VALUE HERE" 00 for memory voltage it'll be like so: 8E 00 "YOUR VALUE HERE" 00.

To change that value to -100mV you'll need to add F0 where i typed "YOUR VALUE HERE" :p ..  If you need extra explanation on how to calculate that, just ask :p

In some cases those values do not exist and you'll need to add them yourself.
In other cases it just isn't possible to edit memory voltage (like my 390 nitro's) <-- check my Nano thread "last post"


Greetings!

Hi Eliovp,
So its a one byte signed value?  I.e. F0 = -16 decimal.  Then I have to muliply by 6.25 to get -100mV offset value
and voila?
If that is all then I've got it and thanks a lot!

[navydude]

This is awesome guys. Just what i was looking for except the only issue is changing the hex. Im not much into code so this is a bit scary to me. I have 12 Sapphire r9 380x cards that i would love to lower the power usage on. I am currently getting around 21.5 mh with stock settings. I dont wanna be below 20mh and that 145w sounds to good to pass up. Would it be possible to get one of you guys to make this rom for me? I really hate to ask but I would rather someone that knows more than me make it.

[bobben2]

This is awesome guys. Just what i was looking for except the only issue is changing the hex. Im not much into code so this is a bit scary to me. I have 12 Sapphire r9 380x cards that i would love to lower the power usage on. I am currently getting around 21.5 mh with stock settings. I dont wanna be below 20mh and that 145w sounds to good to pass up. Would it be possible to get one of you guys to make this rom for me? I really hate to ask but I would rather someone that knows more than me make it.

I will pm you my email address. Then you can send me a copy of the original bios and I will reprogram it and
send you some versions you can test.
If you accept being a guinea pig.