My VRM was idling at 37c and hitting up to 101c under Prime95 AVX2 load, even with a 80mm fan blowing over the top VRMs. The heatsink itself was warm but not too hot to touch under load.
I've read that others had success with replacing the thermal pad and was about to order some fujipoly pads myself but decided to investigate the sinks first.
After removing the VRM sink it became clear what the issue was: not enough pressure on the left side row of mosfets because the imprints left on the thermal pad are barely visible. I had already bottomed out the screws holding the heatsink with no effect.
There are plastic washers glued to the legs of the heatsink, creating a gap over the mosfets. That gap is clearly too big and the lack of a backplate for the VRM sink means the PCB was bowing out a bit, exacerbating the gap.
My solution: put a row of 15x15x0.5mm thick copper shims between the heatsink & thermal pad which lowered my max VRM temp to 70c under the same load WITHOUT an 80mm fan, 30c idle. Ideally, a home made back plate should lower temps even more though.
I have a feeling this is why GB added a tiny 30mm fan for the VRM even though I've never seen anything like it on other flagship boards. They observed the overheating as an issue but did not know the reason for it so they just added the fan in hopes that it'll help.
Great VRM components let down by poor cooling design.
I've read that others had success with replacing the thermal pad and was about to order some fujipoly pads myself but decided to investigate the sinks first.
After removing the VRM sink it became clear what the issue was: not enough pressure on the left side row of mosfets because the imprints left on the thermal pad are barely visible. I had already bottomed out the screws holding the heatsink with no effect.
There are plastic washers glued to the legs of the heatsink, creating a gap over the mosfets. That gap is clearly too big and the lack of a backplate for the VRM sink means the PCB was bowing out a bit, exacerbating the gap.
My solution: put a row of 15x15x0.5mm thick copper shims between the heatsink & thermal pad which lowered my max VRM temp to 70c under the same load WITHOUT an 80mm fan, 30c idle. Ideally, a home made back plate should lower temps even more though.
I have a feeling this is why GB added a tiny 30mm fan for the VRM even though I've never seen anything like it on other flagship boards. They observed the overheating as an issue but did not know the reason for it so they just added the fan in hopes that it'll help.
Great VRM components let down by poor cooling design.
