I installed a new heatsink (came with thermal paste pre-applied), but did not remove the thermal paste leftover from the previous one.
The temps I am getting are idle ~ 28 and full load ~ 70 (prime95).
Should I be concerned? I am worried that since the thermal paste from before has bumps and valleys (it had already dried out when I applied the new one), not all parts of the CPU are being cooled the same.
those temps arent too bad but if it was my own system i wouldnt leave the old paste on there. i would redo it.
95% isopropyl alcohol (available at your pharmacy or most stores in the medicine area) works like a charm. use a q-tip (cotton swab) dippin in it to rub off any old compound (it comes off very easy) then use the dry side of the q-tip to soak up the excess alcohol (but it does evaporate quick). then just wait a minute or two for it to evaporate and you are ready to apply fresh compound.
remember to do both the heatsink base and the chip top.