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There is software to poke around in the NCP81022 chip?

post #1 of 5
Thread Starter 
I saw the thread "Temporary Fix for the 480" and it might fix my own problem, in the other direction.

I own a Sapphire Nitro 380X, that seemly has a very constrained power limit, and throttles a lot (and crashes too, according to this review: http://cxzoid.blogspot.com.br/2015/08/sapphire-r9-380-nitro-review.html )

I wanted to figure its default power limit (ie: what is the W settings for the 0% settings?) and fool around a bit.

Can I send commands to the NCP81022 the card seemly have to control the power, and get replies back? Someone know how to do this?

EDIT: in another forum I also found this link: http://media.digikey.com/pdf/Data%20Sheets/ON%20Semiconductor%20PDFs/NCP81022.pdf
post #2 of 5
The power / OCP (current) limits of the VRM controller are completely independent of the driver (PowerPlay) limit on AMD cards.

The driver limits for Sapphire R9 380X Nitro are:

TDP = 180W (±20%)
TDC = 140A (±20%)

The ±20% figure is the PowerTune limit.

Unless your card shuts down under load, then the controller power and current limits are sufficient. NCP81022 ships with power limit programmed to 300W and most likely the manufacturers don't change it from the default. At least Gigabyte doesn't.
post #3 of 5
Thread Starter 

You are the first person that answer my other question, despite it NOT being the question I asked here tongue.gif

TDP 180W of the 380X refers to the entire PCB?

What is TDC?

I want to figure why the 380X can't keep with the stock clock easily, and how to OC it beyond the factory default (that is seemly already the maximum when considering power...)

Undervolting it by -45mv resulted in a 11% increase in framerate in applications that hit power limit. But also made the driver crash a lot when alt+tabbing between applications (O.o)

Also a couple games, on the resolution I am using (1024x768, thus that allow me to put in all games all settings on "Ultra" and sometimes still have 60fps) using 0% power limit the card throttles a lot, in some drivers it was completely unplayable (Crimson 16.4.x for example GTAV looked like a slideshow).

But I need a new PSU before I go around seriously fooling with power, but for example I would love if I could use the NCP chip to replicate, at least partially, the nVidia's "Perfcap Reason" "sensor", that is very useful.
post #4 of 5
The driver power limit applies on the GPU package only. When the GPU itself draws the full 180W, your card is drawing around 250W from the power supply (VRM losses, secondary power planes, memory, etc). However the driver limits only the GPU power.

TDC is thermal design current, basically a current limit.

Based on reviews of similar R9 380X cards, the total consumption of the card (not just the GPU) should be less than 180W. This means that you should be able to run constantly very close to the maximum advertized clocks (1040MHz) even at stock PowerTune limit. The other factor which can affect the clocks are the temperatures. The VRM controller of the card doesn't support temperature sensing, so most likely throttling isn't VRM related. The throttling temperature limit for the GPU is 95°C and the shutdown occurs at 104°C. If the temperatures are fine, I would imagine it is more a software than a hardware issue.

With PowerTune control set to +20% your effective limits will be 216W (power limit) and 168A (TDC).

If the card is unable to maintain it's advertized clocks even at the +20% PowerTune limit, I would try to:

- Remove all 3rd party GPU related software from the system (e.g. Afterburner, GPU Tweak, Trixx, etc)
- Uninstall the display driver
- Clean all the remaining registry entries with DDU
- Reinstall the display driver
post #5 of 5
Thread Starter 
Thanks for all the information!

But... I still want reply of my original question tongue.gif

I am a very curious person, and the nature of my coutnry (Brazil) where I can't get lots of stuff, means I am used to hacking around (I am building my own chassis for my build, and I will build my own fan controllers, and I convinced Nuvoton to give me the datasheet for my mobo super i/o chip, although I am not sure yet what I will do with that one).

This is why I want to actually poke around the card, see if I can get values out of it. For example in the datasheet I linked I noticed it has registers that are triggered when voltage protection happens, I would love to know how to read that by software.


About my card. I have a Sapphire 380X, Tom's Hardware tested it.


During Metro 4K loop, the average power from PCIe cables (not the slot) was 141W, total (the entire PCB draw) average was 191W

Furmark it reached average from PCIe cable of 186W, and total average was 252W

So, the number you gave me earlier, matches both the total draw during the Metro loop, but also the PCI-e cables draw during Furmark.

So what one was it?

Also, why Furmark even with throttling seemly can still draw that much power? Or the power saving behaviour then was different? (seemly the newer Crimson releases REALLY clamp down the power controls, compared to Catalyst).

And the Watts I see reported as "VDDC in" on Sapphire Trixx for example are what, GPU only? (for example a bug in Mad Games Tycoon today, made the card behave like if a power virus program was running, mail terrible coil whine, the "VDDC in" power on Sapphire Trixx was during that event averaging 120W)

Now back to the review...

On this page:


They test OC, conclude OC doesn't work, because stock already throttles a little.

The behaviour I see from my 380X, is like the graph on the top with the drivers 16.6.1 + 20% power limit, with the "red" version with default voltage, and the "blue" version with -40mv (with drivers 16.4.x it went CONSTANTLY between 1040mhz and 600mhz... AMD told me to test Catalyst 15.11.1, didn't had time to do that yet).

And similarly, running OCCT results in a graph like the second one, but without the "ramp" down, since it is not thermal related, and happens immediately (also the peak temperature during OCCT is about 65C with fans at 70%)

OCCT at 1024x768 (my test screen resolution), on stock settings achieve about 550fps (with error checking enabled). During a test today with +20% power limit, it hit 590fps, and undervolted to -40mv it reached 605fps, and the clock graph looked a lot less "spiky", and more like a solid line at about 980mhz

I saw that in the registry there are some PowerPlay related controls, that Crimson and Catalyst write to the registry in a different manner, and people call it "Crimson Power Saving", I will see what happen if I tweak that AFTER I install a new PSU (if I accidentally draw a humongous amounts of watts I don't trust that my current PSU has enough protections about it).
Edited by OrSpeeder - 7/5/16 at 8:25pm
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