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MP 1,1-5,1 How to - downvolt a Radeon VII
- Thread starter h9826790
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Wanted to share my result limiting max power on my VEGA 56 Reference (blower).
I've manage to limit max power on my VEGA 56 using VGTab by reducing core clock for the P5, P6 and P7 to the same value as P4 (1312Mhz) as it is not possible to down-volt VEGA 56 in macOS.
Running LuxMark max PCIe ampere is 6A (~ 75 Watt on each 6 pin) with Core clock: ~1250Mhz.
Surprisingly LuxMark score still looks good even with the reduced core clock.
PS: I edited the info.plist from the generated VGTab kext's IOProbe to 65051 as mentioned by H98 otherwise it won't load.
I've manage to limit max power on my VEGA 56 using VGTab by reducing core clock for the P5, P6 and P7 to the same value as P4 (1312Mhz) as it is not possible to down-volt VEGA 56 in macOS.
Running LuxMark max PCIe ampere is 6A (~ 75 Watt on each 6 pin) with Core clock: ~1250Mhz.
Surprisingly LuxMark score still looks good even with the reduced core clock.
PS: I edited the info.plist from the generated VGTab kext's IOProbe to 65051 as mentioned by H98 otherwise it won't load.
I just made a kext for 10.15.2 (19C57)
Same procedure as per post #21
Quick test shows good performance as expected. Anyway, good to see that Luxmark can report the correct boost clock speed in Catalina.
Same procedure as per post #21
Quick test shows good performance as expected. Anyway, good to see that Luxmark can report the correct boost clock speed in Catalina.
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@h9826790 First off, thanks for taking the time to look into this. Really useful.
I haven't tested it yet, but will do so during the holiday. Im on watercooling solution for the card, so I want to push the it beyond the standard 1800mhz. At the moment I am running 1100mv in Windows to run 2000gpu/1100ram, stresstested for 6 months and running stable (I can go lower on MV, but sometimes it reboots my system).
Would I need to add 1110mv x 4, and can I set the clock & mem speed to above?
Cheers!
I haven't tested it yet, but will do so during the holiday. Im on watercooling solution for the card, so I want to push the it beyond the standard 1800mhz. At the moment I am running 1100mv in Windows to run 2000gpu/1100ram, stresstested for 6 months and running stable (I can go lower on MV, but sometimes it reboots my system).
Would I need to add 1110mv x 4, and can I set the clock & mem speed to above?
Cheers!
I also tested OC config on my Radeon VII. This parameters works. Basically same as yours. 2000/1100MHz @1100mV.
The most extreme OC on Radeon VII I know so far is 2250MHz @1300mV
Ahh nice - thank you so much, so I can use these. I think I will set max gpu 2000 and mem 1100 (they are 2200 / 1200 on the sheet). 2250 is a big OC.. but 1.3mv - I wouldn’t dare, even doing benchmark.
Is there a certain workflow for when ever there is an OSX update? Like do you have to start all over, even rebuilding a new kext?
Cheers
Is there a certain workflow for when ever there is an OSX update? Like do you have to start all over, even rebuilding a new kext?
Cheers
It was your pre-made kext. Mojave, and the Fans never spin up. Just stay normal slow speed.
My kext won’t affect the PCIe fan.
If the PCIe fan doesn’t spin up, then the GPU should be still quite a bit away from overheating.
Anyway, my kext’s setting only base on my own card with little bit of buffer. It may not fit your chip’s silicon quality. As I said in step a, you better go through step 1-6 in post #1 to find out the actual minimum stable voltage for your card.
I've managed to successfully downvolt my first Radeon VII using the 204w kext, and everything's running really nicely. Plan is to add in a second Radeon VII in the next week or so. Is anything needed to downvolt that as well? Or will it run to the same limits as the first card when plugged in (due to the kext already being in place)?
The PowerPlay table should apply to all Radeon VII automatically.
Would this still work with OC installed for full AMD Accel? Would you put the .kext in the same place as before or within the kext folder on the OC EFI partition?
FYI: I don't recommend using this solution. You are overriding the AMD10000Controller info.plist. If Apple changes something in that file which is required by a new driver version you might get into trouble. So this solution is not update / bulletproof. I strongly recommend to inject the PowerPlay Table ONLY via device properties injected either by PropertyInjector Kext or by using OpenCore.
I attached a PropertyInjector Kext template for reference which includes a PowerPlay Table for RX 5700 XT. Edit it accordingly to match your hardware.
I attached a PropertyInjector Kext template for reference which includes a PowerPlay Table for RX 5700 XT. Edit it accordingly to match your hardware.
Amazing! was just looking for this as my Radeon VII is stuck in warranty repair and have temporarily replaced it with the 5700 XT. Thanks for all your work!
@h9826790, Thanks for your super useful work ! I've just bought a second hand Radeon VII. before I instal the CustomPowerPlay ( post #21) in my cMP 5.1 under 10.14.6, just to be sure : is it normal that this greedy card doesn't boot (only chime then endless black screen) I plugged it in my MP stock with one 8pin connector to dual 6pin and the other 8pin connector to dual power-data (no pyxlas mod) ? is this second hand card has been previously configured for pc (then what should I do to come back in the apple world ?) ??? or is not anymore functional ?? Your point of view would be very appreciated. Thanks !
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The card should boot to 10.14.6 natively with that power config (assume the cables aren't faulty).
There should be no ROM mod for Radeon VII.
But your card won't give your boot screen until your cMP load the macOS GPU driver, that may take up to few minutes (depends on your hardware config).
If you want to see the boot screen after the chime, you need to install OpenCore