Hi lockdown744
TIM (Thermal Interface Material) is measured according to it's thermal conductivity or W/m-K and the higher the better.
Deep Cool DC Z5 is rated at 1.46 W/m-K so to put it bluntly, it's crap.
Deepcool Z9 is rated at 4 W/m-K so is a little better.
You should consider Thermal Grizly, AS5 or MS4 which have a much higher rating exceeding 8 W/m-K.
Yes you pay a little more but it is worth it and you only need a small amount.