RTX 2080 - Ext Fan PWM and RPM not showing

I wasn't able to produce any viable search results on this topic in the forum, so I apologize if I'm asking something that has been answered before.

I have an ASUS GeForce RTX 2080 ROG Strix OC (ROG-STRIX-RTX2080-O8G-GAMING) with 2 fan headers for external fan control. The feature is labelled as "Asus FanConnect II". Other cards from Asus have similar external fan headers as well, so this doesn't seem to be something unique for the 2080 card.

Asus GPU Tweak II shows readings for both PWM and RPM on these two fan headers.

I've tried fiddling around with HWiNFO settings, but these fans do not show up. Does HWiNFO support these fans? If not, any plans to support these in future versions?

Let me know if you need more info.
This feature (at least the PWM%) should be supported on several ASUS models, are you using the latest HWiNFO version?
Please attach the HWiNFO Debug File with sensor data for analysis.
Please try to start HWiNFO new and before launching the scan go into Settings - SMBus/I2C tab - click the "Reset GPU I2C Cache" button.
Let me know if that helped and a new GPU sensor appeared.
Ok, I've tried the cache reset and restarted HWiNFO. I had a good look, but i cannot see any new sensors unfortunately.
Please try to disable the "GPU I2C Caching" option.
If that won't help, please attach a new Debug File after disabling that option.
Alright, I disabled GPU I2C Caching, and did a reset of the GPU I2C Cache, and restarted the program.
Now I see two sensors, that apparently are showing identical data.


I tried another reset of the cache, but it's still showing "double" sensors. And no RPM (I dont know if this can be read outside the Asus Tweak II program).

I've attached another new dbg file in case you want to have a further look at this. Again, let me know if you need more info.


  • HWiNFO64.rar
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I currently don't know how to report RPM, that might depend on type of fan used.
But the PWM % shown now should be correct. Is that in sync with Asus Tweak II? Can you try various fan speeds if they are properly reported?
Would be great to see a comparison of various speeds reported in HWiNFO and Asus Tweak II (including RPM).
I had another good look at the readouts, and it seems there is a single PWM controller for both fan headers. This means it can read separate RPM for each fan header, but the PWM value controls both fan headers simultaneously.

In my case I have two different fans, so I get different RPM values in Asus GPU Tweak II for those two fans, ranging from 0 RPM... to 1300RPM on fan1 and 1700RPM on fan2.

And yes, the PWM % value in Asus GPU Tweak II is identical to what i see in HWiNFO.

Could there be some kinds of "mixup" where PWM data is received instead of RPM values?

For reference here are all the PWM and RPM data points show in the Asus GPU Tweak II program:

Thanks for the feedback.
Could you please try to set 2 or 3 different fan speeds for both of those external fans and create separate HWiNFO Debug Files for each level?
It would be great if the fan levels would be stable during creating those dumps and please include the ASUS reported RPM value in file names of those dump files.
That might help me to determine how to report RPM values for both those fans.