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4090 dropping to 11.59 V minimums

E

Exci

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Dec 6, 2023
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Hello,
I started monitoring my rail voltages with HWinfo and noticed that the FBVDD sensor on my Gigabyte 4090 card (Gaming OC) sometimes drops to 11.59V. The other sensors drop to 11.70V or so, but normally the voltage fluctuates between 11.8-12.0V. I set an alert for under 11.65V and I can hear it beep every minute or two - sometimes within 20 seconds.


voltages.png


I have read that less than 11.7V is not good, but I'm not sure if that refers to the FBVDD sensor. Should I be worried about melted connectors?
I'm running the card at 1mV undervolt (using around 350-360w during the session in the picture), but I'm not sure if that matters. I'm using a Corsair HX1500i PSU with the Corsair cable (goes to two 8-pins). I checked the cable a couple weeks ago (have had the card about a year) and the plug is like new. The connector is tight and plugged in all the way. Haven't noticed a difference swapping between multi-rail and single-rail on the PSU. I haven't really seen anyone reaching these lows so I'm a bit worried. Corsair told me if it only drops to it for a moment it's fine, but I'm quite insecure about it, even if we assume the sensor is a bit off.
 
That is very low. I would be insecure too..

What are the other rails doing while the PSU is busy feeding the 4090?
 
This thread says anything above 11.4V is within spec so you might be okay:

www.overclock.net

How low can the voltage on the 12V rail drop for my GPU...

The title kinda explains it all. I own a XFX Pro 850W and 290 TriX OC, the 12V in GPU-Z shows 11,75V in games, is that OK ? I have observed no instability or crashes, just asking.
www.overclock.net www.overclock.net

Still, check your power supply voltages as well.
 
That does seem like a big swing in voltages especially your min to max seems like a huge range to me
Here is mine undervolted to 0.9V:
1701887472374.png


What version of hwinfo you running? as it says unknown rail voltage maybe its too outdated hwinfo?
 
freeagent said:
That is very low. I would be insecure too..

What are the other rails doing while the PSU is busy feeding the 4090?
Click to expand...
Hmm, not sure what to look for for this one.

oiawshboiwsahnoidaws said:
That does seem like a big swing in voltages especially your min to max seems like a huge range to me
Here is mine undervolted to 0.9V:
View attachment 324387

What version of hwinfo you running? as it says unknown rail voltage maybe its too outdated hwinfo?
Click to expand...
Says v.7.32-4900 so a bit old. I'll update but I guess the existing sensors should be valid. So is the 16-pin voltage the important one?

cst1992 said:
Still, check your power supply voltages as well.
Click to expand...
Hmm, on the iCUE app the voltage stays at 11.9 always. On idle, in-game, exactly at 11.9 (around 38-42A in-game). Is that expected?
 
Last edited:
Does your supply have sense wires (Kelvin contacts)? the idea is that there is a voltage drop across the delivery wires and the sense wires see this so the supply can compensate at its end.

Do you have a volt meter to confirm these values?

I'd not be too worried as the card does not use the 12V directly, but to generate lower voltages.
 
Last edited:
Exci said:
Hello,
I started monitoring my rail voltages with HWinfo and noticed that the FBVDD sensor on my Gigabyte 4090 card (Gaming OC) sometimes drops to 11.59V. The other sensors drop to 11.70V or so, but normally the voltage fluctuates between 11.8-12.0V. I set an alert for under 11.65V and I can hear it beep every minute or two - sometimes within 20 seconds.


View attachment 324383

I have read that less than 11.7V is not good, but I'm not sure if that refers to the FBVDD sensor. Should I be worried about melted connectors?
I'm running the card at 1mV undervolt (using around 350-360w during the session in the picture), but I'm not sure if that matters. I'm using a Corsair HX1500i PSU with the Corsair cable (goes to two 8-pins). I checked the cable a couple weeks ago (have had the card about a year) and the plug is like new. The connector is tight and plugged in all the way. Haven't noticed a difference swapping between multi-rail and single-rail on the PSU. I haven't really seen anyone reaching these lows so I'm a bit worried. Corsair told me if it only drops to it for a moment it's fine, but I'm quite insecure about it, even if we assume the sensor is a bit off.
Click to expand...
Your maximum/minimum range looks about right for a 4090 shifting from full load to zero load. If you're having crashes, then it might be time to worry. However, in absence of any instabilities, you're very likely just fine.

Remember, all 4090s eat a ton of power when under load. You likely have a matching power hungry CPU to go with it. All PSUs experience voltage droop under loads like that. It's not just common, it's expected, even for the highest power, highest quality PSU's.

Be mindful of your system stability. If you start having crashes under load, then you have reason to worry.
 
freeagent said:
What are the 3.3 and 5v lines doing?
Click to expand...
Psu reports 3.3 and 5v. Motherboard reports 3.3V and 5.040V.

lexluthermiester said:
Your maximum/minimum range looks about right for a 4090 shifting from full load to zero load. If you're having crashes, then it might be time to worry. However, in absence of any instabilities, you're very likely just fine.

Remember, all 4090s eat a ton of power when under load. You likely have a matching power hungry CPU to go with it. All PSUs experience voltage droop under loads like that. It's not just common, it's expected, even for the highest power, highest quality PSU's.

Be mindful of your system stability. If you start having crashes under load, then you have reason to worry.
Click to expand...
There's absolutely no instability, fps drops or crashes going on while hwinfo is throwing alerts. I have an 13700K so yes, quite a power hungry system. Honestly if I hadn't checked hwinfo (or..the internet) I'd be a happy gamer.

Shrek said:
Does your supply have sense wires (Kelvin contacts)? the idea is that there is a voltage drop across the delivery wires and the sense wires see this so the supply can compensate at its end.

Do you have a volt meter to confirm these values?

I'd not be too worried as the card does not use the 12V directly, but to generate lower voltages.
Click to expand...
It's not an atx 3.0 psu, so no sense wires (if I understand correctly). I do have a meter but I'm not sure where I could measure without stripping wires.
A bit curious why the psu is supposedly always sending 11.9V. Maybe a sensor issue or PEBKAC.
 
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