One way to undervolt R9 300 series cards by BIOS mod

[playjho]

I'll test this as soon as possible.
Thank you for the advice.

[gupsterg]

Hello there, I followed the instructions of the op to undervolt my Gigabyte r9 390, but when I read the voltage values in the gpu freq table here is what I got :

0   0xA49D   300   Mhz   24-bit   0xA4A0   900
1   0xA4A2   525   Mhz   24-bit   0xA4A5   65282
2   0xA4A7   723   Mhz   24-bit   0xA4AA   65283
3   0xA4AC   883   Mhz   24-bit   0xA4AF   65284
4   0xA4B1   924   Mhz   24-bit   0xA4B4   65285
5   0xA4B6   960   Mhz   24-bit   0xA4B9   65286
6   0xA4BB   994   Mhz   24-bit   0xA4BE   65287
7   0xA4C0   1025   Mhz   24-bit   0xA4C3   65288


As you can see, excepting state 0, the other state voltages are not what I was waiting for.

Do you think it's safe to try values comparable to the values of the op ?

Simply put:-

In all stock ROMs only DPM 0 is manually set VID, so in your example you see 900 (DEC) and unit is mV.

DPM 1 - 7 in all stock ROMs is "auto calculated" VID, the numbers 6528x represents that, the last digit is basically ID of DPM.

Also note in ROM we are setting VID , what we see in software monitoring is VDDC. VID is what the GPU is set to, VDDC is realtime voltage, this will variate due to PowerTune tech / LoadLine Calibration.

[rednoW]

The question is still there. Is it possible to mod memory voltage (not core or aux voltage) on Hawaii via bios editing?

[Eliovp]

The question is still there. Is it possible to mod memory voltage (not core or aux voltage) on Hawaii via bios editing?

I'm pretty sure it's possible on "hawaii" just haven't come across a 390 where it is..

But gupsterg will and can answer that better and more clearly :-)

[gupsterg]

The question is still there. Is it possible to mod memory voltage (not core or aux voltage) on Hawaii via bios editing?

Memory voltage (ie MVDDC) can not changed by bios modification.

IR3567B on Hawaii / Grenada controls VDDC (core) / VDDCI (aux) only.

Only cards which allow software manipulation of MVDDC "out of the box" are Asus 290X Matrix and MSI 290X Lightning, which I don't think most would buy here given the context of use on this forum. So far I have not seen any R9 300 series cards with MVDDC "out of the box".

MVDDC can only be changed with "hard vmod", google the terms 290x mods - kingpincooling.com 1st hit is correct link, in 1st post 1st link is document showing "hard vmod". In this post by The Stilt you'll see it may yield you only small power usage drop.

[Boathouse]

I tried to copy the 900MHz memory strip to the 1000 MHz strip of the XFX R9 390, I found it does not increase the hash speed. Any reason for that?

I thought the memory latency is importnat.

[Docnaster]

The question is still there. Is it possible to mod memory voltage (not core or aux voltage) on Hawaii via bios editing?

Memory voltage (ie MVDDC) can not changed by bios modification.

IR3567B on Hawaii / Grenada controls VDDC (core) / VDDCI (aux) only.

Only cards which allow software manipulation of MVDDC "out of the box" are Asus 290X Matrix and MSI 290X Lightning, which I don't think most would buy here given the context of use on this forum. So far I have not seen any R9 300 series cards with MVDDC "out of the box".

MVDDC can only be changed with "hard vmod", google the terms 290x mods - kingpincooling.com 1st hit is correct link, in 1st post 1st link is document showing "hard vmod". In this post by The Stilt you'll see it may yield you only small power usage drop.

That is bad bad news, according to Elivop, for the 6 R9 nano, if you reduce the mVDDC by 100 mv, it will save 50W. So it should be more for 390 rig.

[cisahasa]

basically easy as this:?

[Next BillG]

basically easy as this:?

That is right. But there are some rule guiding the mod procedure. You need to follow the rules to mod successfully.

[Sarspin]

In the HawaiiBiosReader, where do we change the default GPU core/memory frequency? I want default to be 950/1000MHz.

[Docnaster]

In the HawaiiBiosReader, where do we change the default GPU core/memory frequency? I want default to be 950/1000MHz.

In the picture above, you change the GPU/Mem clock 1 from 1000/1250 to 950 1000. that should work for you.

[Next BillG]

In the HawaiiBiosReader, where do we change the default GPU core/memory frequency? I want default to be 950/1000MHz.

In the picture above, you change the GPU/Mem clock 1 from 1000/1250 to 950 1000. that should work for you.

I tried the above procedure. It is working well.

[Masked_Immortal]

I tried to undervolt my gigabyte r9 390 via  this method, as you know these cards are voltage locked!
i started with 1060 as final voltage and go up to 1130...
but no success, stability issue in dual mining, any further voltage does not has considerable effect on temperature

[Zistmine]

I tried to undervolt my gigabyte r9 390 via  this method, as you know these cards are voltage locked!
i started with 1060 as final voltage and go up to 1130...
but no success, stability issue in dual mining, any further voltage does not has considerable effect on temperature

You just need to reduce the core frequency to increase the stability. I run the core at 970 MHz at 984 mV.

[sp_]

I saved 160Watt per card with a homemade modded bios. Gigabyte G1 390. (using the claymore dual miner)

Etherum: 27MHASH
siacoin: 415MHASH.

The voltage is not locked, you need to use a hex editor and reverse engeneering. (cracking)

[Boathouse]

I saved 160Watt per card with a homemade modded bios. Gigabyte G1 390. (using the claymore dual miner)

Etherum: 27MHASH
siacoin: 415MHASH.

The voltage is not locked, you need to use a hex editor and reverse engeneering. (cracking)

You said you saved 160W per card. What is the power consumption per card on the wall after the mod?

[Calivet]

when you say 160w do you mean 160w measured at the wall or after you have calculated it with the power efficiency of your psu?

[Mzie]

Thanks will look into that

[naum1881]

Hi Bobben 2,

thx for your detailed post. Everything is fine for our R9 390 cards in common, but we really expected some troubles in stability with only several cards out of 100+.

You've already edited bios for 380X, could you, pls., share it with us?


Thank you in advance.

[adaseb]

I got a 390 ASUS STRIK and just wondering whats the best efficiency one has gotten.

So far the best I can do is 1.03V (shown in MSI afterburner voltages)  at 1050/1500 and its about 7.5W/MHS.