The thermal pad on recent AMD OEM HSFs is Shin Etsu phase
change material (gray) - top notch stuff. You can get replacements
from frozencpu.co or ajigo.com. As mentioned by others above,
when applied properly it should last the life of the installation. The
melt point of the Shin Etsu material is 48 deg.C. It should be only
be allowed to get above that temp at installation - ONE melt. After
that, temp should be maintained below 48 deg.C or it can get
pumped out just like the greases. All PC TIMs should be done this
way. I prefer the stuff AMD used before (Chomerics T725) which
had a higher melt point so you didn't have to worry so much about
remelts. I've also seen the Thermagon (T-pcm905C) out there -
mainly on eBay for a good price - I don't know the melt point on
that (now I do, over 70 deg.C for 5 min.). And the Honeywell
PCM45 stuff has a 45 deg.C melt point.
. IAC, the max die temp of most AMD open die procs is 80 deg.C
or more - but I like to keep mine in the low 50s or less. It's up to the
system integrator to design to the desired temp.
. My Duron 1600 hardly ever gets out ot the 30s anyway - no
worries about remelt here
🙂 .
. AMD recommends pads for Duron/Athlon/XP (bare die CPUs)
and greases for "capped" CPUs (w/ heat spreader) like the 64-bit
procs. Though there are thick pads out there that can fill the gaps
even on capped procs - but I guess AMD doesn't recommend
them. If you lap your heatsink, you should have no trouble with pads
even on the capped procs.
AMD comparison of TIMs
AMD Design Guide (includes table of recommended PC TIMs)
.bh.