Thermal sensor dieing or something else?

[Armadillo]

My 2nd machine uses my old 5850 & while it's working fine the temperatures seem odd.

Basically, it idles at about 50C. The very instant you open a game, the temp instantly jumps to around 67C, then makes another instant jump to 95C or so.The second you stop using 3d clocks, it pretty much instantly drops again.

It never used to do it, it used to make a slow gradual climb and slowly cool down as expected.

When it's apparently 90C+, I've had the side panel off and the card does not feel that hot.

Can a temp sensor just give up and die? or something else at play. Thermal paste has never been changed, could that cause it, I would have thought you would still have a gradual climb though.

Fan is working and games are fine, no throttling or artifacts, but then I'm not sure when a 5850 would start to throttle anyway.

Thanks.

 

[Armadillo]

Thanks. I'll change out the paste then, see how it goes.

Quick edit because I don't want to double post.

Thermal paste must have been on it's death bed. Before changing. Idle 50C, instantly spiking to 67C, then 90+. Fresh mx4 on there. Idle 28C, gaming 53C. Gradual climb, no spike.

Always thought when thermal paste went bad, temps would just be higher. Didn't think it would spike like that.

 

[Armadillo]

Was it white and powdery when you took it off?

It was still grey, but it was hard and came off in chunks when I wiped it away.