Alphacool Eisblock Aurora Acryl GPX-N RTX 3080/3090 FTW3 thermal pad replacement

[DaveW]

Post this separately so it's not part of a solved thread. I'm seeing quite high junction temperatures on my 3080 FTW3 with the Aurora, around 100°C under full load with 22°C water temperature and 36°C core temp. I am looking at disassembling my card and reapplying, but want to be ready to replace the memory pads if they get damaged in the process. Would the Alphacool Eisschicht Ultra Soft thermal pad 3W / mk 100x100x1mm be the equivalent to the whitish 1mm pads that are included with the block?

If I replaced them with the 11W/mk thermal pads (pn 12456) would 1mm still be the appropriate thickness for that location? I haven't taken it apart to see the compression on the existing pads yet. Thanks

 

[Eddy]

When you take off the cowl, take a look at the imprints of the WLP pads. They may not be in proper contact with the ram. Since the GPUs at Nvidia vary in height due to high manufacturing tolerances, this can lead precisely to the cooler not being able to be pressed on far enough.
You can see this in the contact pressure.

And yes, these are exactly the same heat conducting pads as on the cooler.

 

[DaveW]

As an update on this, compression on the supplied pads looked good, so I replaced them with t-global A1780 1mm pads. Memory junction temps went down from 100°C at +1500MHz memory (10750) to 64°C at +1700 (10950).

 

[Eddy]

Great

 

[coccosoids]

As an update on this, compression on the supplied pads looked good, so I replaced them with t-global A1780 1mm pads. Memory junction temps went down from 100°C at +1500MHz memory (10750) to 64°C at +1700 (10950).

Does this mean that the thermal pads supplied with the waterblocks are virtually unusable?

 

[Daniel]

The thermal pads are not the problem here.
As Eddy stated Nvidia GPU's can vary in height due to high manufacturing tolerances.

We had a few cases now where that was the case. Still very few though.

 

[coccosoids]

The thermal pads are not the problem here.
As Eddy stated Nvidia GPU's can vary in height due to high manufacturing tolerances.

We had a few cases now where that was the case. Still very few though.

@DaveW said he replaced the pads with t-global A1780 1mm. He also said that the compression was good, yet he still replaced them. So just by swapping the stock pads included with the waterblock (1mm) with a different brand but with presumably higher conductivity but still 1mm thick, he managed to lower junction temps from 100C to 64C:

I replaced them with t-global A1780 1mm pads. Memory junction temps went down from 100°C at +1500MHz memory (10750) to 64°C at +1700 (10950).

 

[Daniel]

He also said that the compression was good

Missed that one...
But well a decrease of 36°C(!) by only changing the thermal pads is highly unlikely. Something else must have been wrong here.

 

[DaveW]

I could see indentations in the pads from the memory dies, so it would appear that there was good contact. It could have been marginal before though, as increased mounting pressure will reduce thermal resistance.

The only other modification was replacing the small thermal pads at the back with a large sheet of 3mm 6.8W/mK between the back of the board and the backplate instead of the small included strips. I am unsure how much of a difference that actually makes, but should help lower the overall PCB temperature.