Tried the $5 thermal paste vs the $20 tube and guess what happened

I was rebuilding an old Dell Optiplex from 2011 last week and ran out of thermal paste. Grabbed some cheap generic stuff from a local shop for $5 instead of my usual Arctic Silver. Three days later the CPU fan was screaming nonstop and temps hit 85C at idle. Swapped it for the $20 tube and dropped 20 degrees. Has anyone else had a cheap paste fail on them like this or did I just get a bad batch?

2 comments

2 Comments

jakewhite6d ago

Did you check if the cheap stuff was electrically conductive? I made that mistake once and almost fried a board because the paste was basically a metal slushie lol. The cheap tubes often use aluminum or zinc oxide fillers which can dry out fast or pump out under heat cycles while the good stuff uses boron nitride or silver particles that hold up way better over time. At $20 you're basically paying for consistency and not having to reapply in 6 months.

kim.wren6d ago

Did you ever test the thermal cycle life on that cheap stuff, @jakewhite?