Hey guys

So I've just rebuilt my computer with a nice new power supply, mobo, cpu, and ram. I've kept my old GPU, which is a GTX 770 with an NZXT Kraken G10 bracket, and a Corsair H55 cooler. The fan is a Noctua NF-F12 3000rpm. All of this is attached to an NZXT Grid+.

When I load the GPU, even with both the pump and radiator fan maxed out on the Grid control panel, temps quickly skyrocket (if left unchecked, they hit the card's limit of 98 degrees Celsius extremely quickly). The fan is DEFINITELY pumping enough air through the radiator, I can feel the airflow out the other side of it.

When the card is idle, it sits around 34 degrees. When I turn the pump off, the temps begin to climb slowly - as is expected. However, the fan seems to have no impact whatsoever on the temperature of the card. Turning off the fan completely makes no difference to the temperature, compared to the fan going the full 3000 RPM.

This is all very different behaviour to what was happening a couple of weeks ago in the previous iteration of this computer. Note the VRMs and VRAM temperatures are fine and normal.

In Afterburner, when I set temperature limit to 80 deg C, the card successfuly limits itself to that temperature. However clock speeds are down anywhere between 200 and 500MHz, so that obviously isn't helping the issue.

I've taken off all overclocks to the card, even the factory one.

See picture for the layout of my case:
Click image for larger version. 

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Any ideas would be much appreciated. I think tomorrow I'm going to replace the thermal paste just in case it's that.