Non-conductive & Non-capacitive --- ONLY --- if they over spread no harm no issue
 
MX-4  = my vote
 
 

Thermal paste roundup 2015
 
Prolimatech PK-3 ---- looked the best delta T
 
 
TIM that has little or NO curing time & does not dry out --- is what you want to go with 
 

I think I read that ek ECTOTHERM  is rebranded MX-4
 
Must not be MX-4 because thats in the chart. 
 
check out this chart
 
http://www.eteknix.com/ek-releases-ectotherm-thermal-compound-retail-packaging/
 

ARCTIC MX‑4 Thermal Paste is still my Vote.

Woot
 
Bring on the Pics
 
Living life on the edge - 10 min leak test

I used IC Diamond as well for years. My first build was back in 09 when the 1156 cpu chip and the 480 hydrocopper made its debut. I ran IC Diamond on the Cpu and Gpu since Last thursday( 7 year outdated). At the time, it was the best on the market, so I couldn't tell you the difference between that versus a lesser brand. I think over the 7 year span, I reapplied maybe 3 or 4 times, only because of tubing upgrades and just regular maintenance/cleaning of the build. It never let me down. It was though, not dried up, but not fresh either. it was like a soft playdough, wet clay, etc. Easy to take off with alcohol like any other TIM, but never dried up.
 
This go around, I bought some Gelid GC Extreme off of the EK website when I bought my blocks( cpu/gpu) along with a long awaited upgrade(6700/1070 SC/z170 ftw/16gb vengeance ram). My current temps, as I type this are 25 cpu and 26 gpu running default clocks. I have IC Diamond left over, but maybe only enough to do one chip and not both. So I couldn't give you a proper comparison between the two TIM's. But this GC Extreme seems to be pretty great stuff, non conductive, non-everything. Cpu i applied it with a blob in the center, and the Gpu i blobbed it, then spread it even with the little applicator they provide with the GC Extreme. That way, you know the whole thing is covered, and you don't have to worry about bad spread