afaik the rated voltage for eg. samsung memory at 2000mhz is 1.35 volt.
Older gddr5 chips were normally 1.5 or even 1.6 volt.
So setting it to 800mv without crashing is a sure sign it doesn't work.
Which is a pitty because most performance could probably be squeezed by upping mvdd. (not vddci)
Older gddr5 chips were normally 1.5 or even 1.6 volt.
So setting it to 800mv without crashing is a sure sign it doesn't work.
Which is a pitty because most performance could probably be squeezed by upping mvdd. (not vddci)
Yeah, I tested myself and I do believe you're correct. It does seem to work on Fiji, IIRC, but probably because HBM.
Mentioned this a few times already, but i'll do it again
Fiji and Those Lightning cards are the only ones capable of directly modifying the memory voltage (MVDDC or how it has been referred here "MVDD").
For every other card out there (i could have missed one or two) you can only raise or reduce the voltage given to the controller (VDDCI/AUX).
This isn't even stock, to be able to do this, you'll need to add the needed offsets in the rom, therefor also needing to remove extra whitespace in the rom to get the exact same size again. Not only that, the tables in the rom have to be modified as well. i2cdump ...
So basically, at this point, by opening polariseditor or wattman or whatever, and changing the voltage value next to the memory is not going to apply directly to the memory, but to the controller, so basically, giving that controller extra voltage does not affect your memory directly as that memory isn't getting extra voltage.
Could we just change vddci in Linux using pp_table?
After parsing it seems vddci is there:
Container:
ucRevId = 0
ucNumEntries = 2
ATOM_MCLK_ENTRY = [
Container:
ucVddcInd = 0
usVddci = 850
usVddgfxOffset = 0
usMvdd = 1000
ulMclk = 30000
usReserved = 0
Container:
ucVddcInd = 15
usVddci = 950
usVddgfxOffset = 0
usMvdd = 1000
ulMclk = 220000
usReserved = 0
]
This is only for the controller, and other shit (AUX voltage.)
Tested setting values for vddci other than 950 for mclk 2200MHz.
Immediate crash.
I'm finishing up testing on my tool for this, and it will do 900 - 1000 for me, but 1025 is too much (NSFW): https://ottrbutt.com/tmp/wolfamdctrl-v1-testing.png
Care to share src?
I've been playing with pp_mclk_od and pp sclk_od, but setting up voltages would be awesome!
How do voltage mod work with normal amdgpu-pro drivers on a 4.4 kernel?
Thx!
