XPS17 Post Repaste GPU Temp

So, I've just recently done a thermal repaste on the heatsinks of my XPS17, and the temperature on both the CPU and GPU has dropped from 90-95C on high load to about 50-70C.

That's all well and good, but I find that when idle, the fan now turns on and off every few seconds, and the temperature of the GPU fluctuates from 0c to around 45-50C every other second.

When I run a game, and the GPU is under load, the temperature stays constant and the GPU doesn't overheat, so the thermal paste is doing its job moving the heat from the processor to the heatsink. I figure that it has something to do with power saving but I just wanted to make sure I did the job right.

 

What do you mean when you say the temp on the GPU fluctuates from 0C?

Sent from my XT1575 using Tapatalk

 

The temperature monitor I use, regardless if it's GPUZ or CAM, etc, shows a reading of 0C one second, then 45C the next second, and back to 0C, and so on. It results in a graph that looks very spiky, to say the least.

 

Well, that is definitely a quirky behavior.

In any case, there are two things I can think of:

1) Let's assume your GPU temperatures originally were high enough that the fan was constantly on at low RPM. Your repaste job was so good, that you lowered the temperature of your GPU so that the fan doesn't even need to turn on at idle. Occasionally, enough heat builds up where it needs to turn on for a few seconds. But then in quickly cools things back down to where the fan can turn off. So your fan is actually spinning LESS as a total amount of time. But the on/off behavior makes you notice the fan more than if it was just always on at low RPM.

or

2) You damaged your GPU temperature sensor during your repaste job. And it is the temperature sensor that is sending fluctuating readings of 0C --> 45C every few seconds. And when it sends a "45C" temperature, the fan profile tells the fan to turn on. When the temperature sensor glitches / fails and reads "0C", the fan turns off.


You can test scenario #1 by asking other people what their fan behavior and temperature is, as a stock and untouched XPS 15 system. You want to know what the idle temp of the GPU is, and the default fan behavior when the XPS 15 is idling.
You can test scenario #2 by using different programs that read GPU temp, to see if they all return the same quirky 0C --> 45C behavior. You might try also re-pasting the GPU to see if that helps to "reseat" anything. But re-pasting the GPU may also do further damage, and finish the job of completely killing off your GPU temperature sensor once you disturb it again.

I'm hoping, for your sake, that it's just some quirky software problem. Because the other option is ugly.

 

kent1146, I really appreciate your in depth and prompt reply. Thank you

I read a few other posts about similar fluctuating readings, and one other option was to reinstall the graphics drivers, BIOS, and flash it. That seems to have done the trick, because it's idling at 40c now, and the cycling behavior seems to have ceased. I'm just amazed at the difference new paste can make. It's like a new computer.

So yes, I would say that the first case you mentioned was the issue. Hopefully, this thread could help others in the same situation.