Aorus RTX 3080 Xtreme 8-pin #2 Voltage

[astral]

Hey all, while I was checking my temps to see how they currently are at full load, I noticed my GPU 8-Pin #2 would go down to 11.5V. Is this fine? Possibly, using software to check these figures ain't the best tool. I also ran HWInfo and GPU-Z separately to avoid any sensor confusion. Power draw seems fine but I do notice the pin 2 has the lowest draw. The card is stable even when it's overclocked, passes stress tests.

Additional background info - I had this card repaired, I accidentally got one of the choke capacitors off when I was taking off one of the fan headers during thermal pads replacement. Before this incident, I checked my old photos and saw that the 8-pin 2 wouldn't go down as low as 11.5V. only 11.9, just like the others.

Also, ever since it was repaired, the White LED's which means "PSU abnormalities" would turn on, but the card is stable. However, when the GPU is loaded, the white LED's would shut down. Then it would come back on the moment the fans enter 0 RPM mode.

Was the soldering not done properly? Or is this now a male to female pin contact issue?

GPU: Aorus RTX 3080 Xtreme

PSU: Corsair RM850i - All 8-Pin plugs have their own cables and not daisy chained.

Thank in advance!

 

[TomWoB]

Hi astral,

the ATX specification says the following: ATX 12V power must be between 11.4 V and 12.6 V (ATX 12 V +/- 5%)

So, your 11.5 V is still within specification. I think it can be your soldering. Let's have a look at the power consumption; a RTX 3080 consumes max 340 Watts. 75 Watt can be taken from PCI-slot, so around 260 Watt is taken from cable connectors, 130 Watts each. At 12V you have 11 ampere current on each cable. If your soldering has an electrical resistance of 0.04 Ohm. you have the 0.4 V drop-down (11.9-> 11.5). 0.04 Ohm is really low value, so the reason can be your soldering.

But you can check this: reduce the power consumption of your RTX 3080 to a minimum, no game, just a "static Windows screen", like a maximized Explorer-window. What is the voltage now? If you have the following situation

• low power consumption (Explorer) = high voltage (approx 12V)
• high power consumption (Gaming) = low voltage (your 11.5V)

Then you have "some electrical resistance" between your power supply and the voltage sensor on your RTX 3080 !

But, as I said above, your system is still within ATX specifiation ... that's why it still works properly.

Regards
Tom

 

[astral]

Hi Tom, thanks for the reply! Really appreciate the info and learned something new today. Probably the person who resoldered the capacitor didn't do a clean job and did not check properly the voltages.

To answer your question:

• Low power consumption - 11.8 - 12.0 V (approx 12)
• High power consumption (gaming) - 11.5 -ish to 11.6 with a rare 11.45x (You may refer to attached screenshot)
• I noticed however during mining, with undervolt settings and memory overclock, it would go down to as low as 11.1 V but on average it is 11.2-11.3V.

Prior to posting my inquiry, I also ordered CRC QD Electronic Cleaner as I was hoping that it was more of a contact issue between the plugs.

May I clarify also, since there is "electrical resistance" between the PSU and the voltage sensor, is this strictly just the sensor saying it is below 12V but in actuality it is receiving the proper voltage?

Regards,
Astral.

 

[TomWoB]

Hi Astral,

the "electrical resistance" can be anywhere between power supply and voltage sensor: maybe first plug power supply -> cable, or second plug cable -> graphic card, or soldering point. I think soldering point, because "this has changed" and since soldering with lead is forbitten, soldering is more difficult. Maybe temperature was wrong (too low) or there was a small shock during cool down process -> "cold soldering point" ... but I don't really know ... I can't know (?)

And don't forget, the "electrical resistance" seems to be very low ... approx 0.1 Ohm or less. The voltage dropdown depends on "electrical resistance" and on "current value" ... which is typically high for graphic card power, up to 10 Ampere! The chips on the graphic card needs only "one volt or a little bit more", so the voltage is anyway "downgraded to chip voltages" on the card. Maybe the fans need 12V, but not the chips (GPU and VRAM). The "12V voltage" is used to deliver 130W "successful" to graphic card ( P (Watt) = U (Volt) * I (Ampere). If we use 5V for graphic card power, the current has to be increased to 25 Ampere -> the voltage dropdown on the "eletrical resistance" will be increased to 1.2 V: U (Volt) = R (Ohm) * I (Ampere) -> your graphic card will not longer work properly, because graphic power is outside ATX specification. Btw: for the same reason, the lines of electric power plants have voltages of up to 700,000 Volts, to keep the current low (thinner = cheaper cables needed and less losses).

Hope this was not too technical ...

Regards
Tom

 

[astral]

I see! It was a little technical but I enjoyed it! I'll try the contact cleaner when it arrives and I'll plug this on a different system to rule out the causes.

I'll share updates here when I can.

Thanks!