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6900XT Power Limit Tricks
Jon was nice enough to send me some test builds of the XDPE132G50 IC that controls the vrm on the 6900XT. Trying each value one by one we found we were able to greatly reduce the power sense output similar to what a shunt mod does on Nvidia. Since there are no shunts....this is the way.
Start by flashing up your firmware, I am using 8e.
Latest firmware: https://www.elmorlabs.com/index.php/forum/topic/evc2-beta-firmware/
Next grab the software with the new profile for our 6900XT PWM.
EVC2 1.0.1.6b: https://1drv.ms/u/s!Atmpv-6qHr_6zNMcyHhTGInugB-uqg?e=TASvPG
Now you want to slap on your SDA/SCL/GND (pics courtesy of Elmor) you can use either spot, I used the IOR controller spot so I could just grab the screw mount for sure ground.
After that, I suggest reinstalling some fresh drivers especially if you have been playing with MPT at all. Everything went much smoother that way. Next just to verify everything is working I suggest you run a stock clock run of whatever gpu bench you like with GPUZ logging max GPU wattage / temp / and clock. Here is my before and after.
Settings for XDPE
Settings for IR35217
With more breathing room the card was able to run 2700-2800 set in AMD overdrive on water cooling for Fire Strike Ultra. The efficiency is really great when the wattage use is low like this.
Some snags I ran into: some sort of protection when using in my case too much voltage (1.10) the computer would shut down under load lowering it let me pass (1.05). You will run into a point also where adding more vGPU is letting you increase your clocks that you set but the score will be worse or not change. Running at the bleeding edge you should also take note that the driver sometimes needs to be refreshed if you keep failing a specific test for no reason. I tried adding MPT into the mix to push even further but changing any setting at all really made my score drop. Maybe others will have more success there.
If anyone gives it a shot let me know how it works out and if you have anything to add. Cheers and happy new year!
Uploaded files:
Original picture courtesy of https://www.techpowerup.com/review/amd-radeon-rx-6900-xt/5.html 🙂
Working great on ln2. Hold clocks closer to the target judging from 3dmark system info average. Now I just need bypass the black screen at -65c 😆
After 2850 real mhz things are not really improving score wise. Can set 2900 and pass but the real mhz are lower and scores worse. Need to play more.
Thanks a lot Allen and Elmor. Will give it a go this week and give you guys my feedback and findings.
Elmor's evc2 feedback -
Installed my evc2s yesterday on my non-reference pcb and it works wonders. Been a non-reference pcb i was able to tweak XDPE312G5 only as it does not detect any other ICs. evc2 works wonders when i apply the tweak volt settings for the XDPE312G5. Before installing the evc2 i ran some test on FSU and it reports max 348 chip power draw. After installing evc2 and use the volt guide Allen and Jon posted max chip power draw was 242 and got an increase on the score of ~180 points , so it is working as intended.
Efficiency using evc2 + low volts + lower clocks is huge when compared to just using mpt and/or High max clocks on the core and memory and max volts 1.175v. I beat my old best scores at much lower clocks this way as i suspect some kind of throttling is happening inside the gpu and not been reported or some weird Bios or driver behavior pulling down the scores inefficient runs. My old scores where done using mpt with an increase pl of 550w and 1.20v on v.core at max core clocks of 2850/2150Mhz maxed out my 6900xt and was run on water chiller at -21c , my new scores were done with installed evc2 only and i did not use mpt as it started acting weird and got lower scores with the mix of evc2 and mpt. With only 2750/2130Mhz clocks and 1.08~1.10v lower clocks and lower voltage i was able to beat all my old runs done at higher clocks and higher voltage. I can confident say 100% that evc2 is the way to go on this RX 6xxx video cards. It's like a triangle that you have to balance to make all the lines straight and line up at 60% angle for a perfect balance equilateral triangle = Power limit / v.core / clocks. It is a balancing act and it takes time to tweak , but once you find the sweet spot you are golden 👍.
Seems like a good tool, put a evc2sx on order.
From what I can understand it seems like you can freely adjust voltages and offset the reported power draw (to effectively increase the power limit).
But it would also seem like there's still some voltage protection limit on the card that prevents using "too much" voltage?
Am I understanding you guys correctly?
I'm primarily trying to raise the 1175mV limit (and significantly raise the power limit). To utilize a custom cooling solution to push the frequency close to the 3000MHz limit. Or as close as I can get.
Quote from No-one_no1 on 2021-02-04, 19:52Seems like a good tool, put a evc2sx on order.
From what I can understand it seems like you can freely adjust voltages and offset the reported power draw (to effectively increase the power limit).
But it would also seem like there's still some voltage protection limit on the card that prevents using "too much" voltage?Am I understanding you guys correctly?
I'm primarily trying to raise the 1175mV limit (and significantly raise the power limit). To utilize a custom cooling solution to push the frequency close to the 3000MHz limit. Or as close as I can get.
Hello, there should be no limit for high voltage you can apply except for the programmable Vmax register of the controller and the controller max capable voltage (over 2V). You can adjust the Vmax value yourself to prevent any accidental setting applying a lethal voltage for your GPU.
Okay I just ordered the evc2sx and first time using this mod so I need to fire off some questions besides clearing out MPT and reinstalling fresh drivers
- would I just use the voltage controls under the evc settings and leave the amd driver side stock or does that edit those also.. Example if i want to run my 6900xt @ 1.25v do I only change that with the evc2 software and leave wattman default or max out wattman and read the vcore with the controller and then change it
- does the EVC2 need to be set every reboot and or plugged in at all times , I assume it needs to be just want to be clear want to use it 24/7 not just benching
what is the best way to set the voltage, I want to shoot for 1.25 vcore first time using the mod. Installed it yesterday detects all controllers updated the firmware and using 1.0.1.7 software.
Quote from hyperc on 2021-06-20, 06:25what is the best way to set the voltage, I want to shoot for 1.25 vcore first time using the mod. Installed it yesterday detects all controllers updated the firmware and using 1.0.1.7 software.
Hello, the current way of adjusting voltage will add an offset to the VID requested by the GPU. So if the card is currently running at 1.100 V and you apply +50mV offset, it will be 1.150 V.
