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ASUS ROG Strix RTX 3090

The graphics card I2C bus is accessible using PCON1/PCON2/SCON2 headers (all connected together). PCB pictures for reference: https://www.techpowerup.com/review/asus-geforce-rtx-3090-strix-oc/3.html

List of controllers

  • MP2888A 0x20 (GPU) (can be split from MSVDD to addr 0x21)
  • MP2888A 0x20 (MSVDD) (can be split from GPU to addr 0x22)
  • uP9512 0x27 (Memory)

Splitting GPU & MSVDD controllers

You can separate the address of the two MP2888A controllers.

  1. Check that the controllers above are found
  2. Send a custom I2C command Addr = 0x20, Cmd = 0xBE, Cmd Length = 1, Data = 0x20, Data Length = 1
  3. Press Find devices again and you should find two MP2888A controllers on addresses 0x21 (GPU) and 0x22 (MSVDD)

MP2888A notes

  • Change Vout Control to PMBus to enable Vout Command & Vout Offset functions
  • Vout Max limits the highest possible voltage you can set, above a certain point it may need to be increased
  • Output Voltage reflects the true measured voltage as seen by the controller and is usually a few tens of mV below the applied value

uP9512 notes

  • SMBus Lock needs to be set to Unlocked before any changes will apply
  • If SMBus Lock = Locked, the controller has been locked by BIOS or software. After it has been locked it needs to be power cycled before it can be unlocked again. You can try to prevent the lock from being set by using the "Lock bus" option.
  • Voltage Command Control needs to be set to Enabled before the Voltage Offset can be applied
  • Some users reported having to set Auto Phase to Disabled (SMBus) before being able to make changes
  • The Voltage Offset is limited to 0 to +150mV by the controller design

edit: SCON2 is connected to PCON1/2, not SCON1

edit2: Added more details and pictures

Uploaded files:
  • Strix.png
  • PCON1_2.png
  • SCON2.png
  • split.png
Glenn99 has reacted to this post.
Glenn99

 

Quote from elmor on 2020-12-04, 14:55

Accessible over I2C using PCON1/PCON2/SCON1 headers (all connected together).

I had a question about this. Have we found if it's possible to control the MSVDD separately from the GPU voltage?

Continuation testing showed PCON 1/2 are definitely connected but I couldn't get continuation with either for SCON 1. 

The pcb has two MP2888A's, presumably one each for gpu and MSVDD. Really odd to not be able to control them independently from each other.

 

Cheers!

 

Quote from jomama22 on 2021-01-14, 04:49

 

Quote from elmor on 2020-12-04, 14:55

Accessible over I2C using PCON1/PCON2/SCON1 headers (all connected together).

I had a question about this. Have we found if it's possible to control the MSVDD separately from the GPU voltage?

Continuation testing showed PCON 1/2 are definitely connected but I couldn't get continuation with either for SCON 1. 

The pcb has two MP2888A's, presumably one each for gpu and MSVDD. Really odd to not be able to control them independently from each other.

 

Cheers!

 

Not yet, SCON1 is my mistake. It's supposed to be SCON2 that's connected to PCON1/2. I'll update the first post.

Quote from elmor on 2020-12-04, 14:55

 

  • uP9512 0x27 (Memory)

 

A bit a weird question, but is it possible to reduce the Memory Voltage? 
I soldered the EVC2 to my Strix and in order of some testings, i want to reduce the memory voltage.

But.. there is only a possiblity to change the offset higher and not lower. Is there any way to achieve my goal to reduce VMem with the EVC?

Quote from xtremefunky on 2021-01-26, 21:37
Quote from elmor on 2020-12-04, 14:55

 

  • uP9512 0x27 (Memory)

 

A bit a weird question, but is it possible to reduce the Memory Voltage? 
I soldered the EVC2 to my Strix and in order of some testings, i want to reduce the memory voltage.

But.. there is only a possiblity to change the offset higher and not lower. Is there any way to achieve my goal to reduce VMem with the EVC?

Hello, voltage control on uP9512 is very limited through I2C and only offers adding 0 - 150mV. You could as an alternative rely on adjusting the voltage on the REFIN pin using the VMOD1 header as described here: https://www.elmorlabs.com/index.php/forum/topic/evc2-vmod1-header-tutorial/

 

Quote from elmor on 2021-01-27, 16:36
Quote from xtremefunky on 2021-01-26, 21:37
Quote from elmor on 2020-12-04, 14:55

 

  • uP9512 0x27 (Memory)

 

A bit a weird question, but is it possible to reduce the Memory Voltage? 
I soldered the EVC2 to my Strix and in order of some testings, i want to reduce the memory voltage.

But.. there is only a possiblity to change the offset higher and not lower. Is there any way to achieve my goal to reduce VMem with the EVC?

Hello, voltage control on uP9512 is very limited through I2C and only offers adding 0 - 150mV. You could as an alternative rely on adjusting the voltage on the REFIN pin using the VMOD1 header as described here: https://www.elmorlabs.com/index.php/forum/topic/evc2-vmod1-header-tutorial/

 

okay thank you for your reply. Hmmm.. thats a cool workaround, but sady lot not was I was expecting... 

UPDATE :  after Elmor's advice in Discord, problem solved, re-soldering fixed it. 

 

 

Per printscreen, my EVC2SX with app 1.0.1.7 has a 'Bus Low / In Use' error, is there a common cause for that ? This is my first EVC2 install and run.

Disabling Afterburner and several re-boots without anything else started didn't help, nor did switching from I2C1 to 2.

In Afterburner with EVC2 connected the voltage switched every 2 seconds or so between some 740mv an 0mv. Youtube in the background ran fine.

Am not the best solderer but the wires seemed ok. Before opening it up again I need to check whether it can be anything else.

Did find a post on overclock.net with someone having the same issue : "The only issue is getting the damn controller to read without getting a bus low error. I have to fully shut down my pc for hours and enter evc software immediately after boot. I'm sure there's an easier way but I haven't found it yet."

 

Uploaded files:
  • evc2-error-3090-strix.png