Raspberry Pi manufacturer has stated that you donβt need heatsink for the normal operation of the Raspberry Pi device, however overclocked or heavily stressed devices will benefit from heatsink installation.
I decided to compare available heatsinks on the market and have found the best heatsink for Raspberry Pi 3.
First tested heatsink is small β 14x14x6mm, priced 1$ on Ebay
It has an adhesive layer for mounting on CPU.
Second heatsink β is larger 50x25x10mm, also priced 1$
Mounting was done with Arctic Silver thermal compound and super-glue π Thermal compound was applied to the center and glue β to the corners of the chip.
Please note that this will be a permanent solution, and you will not be able to remove the heatsink.
For loading the CPU I used stress software (apt-get install stress).
Only 1 core of Raspberry Pi 3 was loaded β frequencies: arm_freq=1290 core_freq=430
Here are the temperature graphs:
Red line β no heatsink.
Blue β small heatsink 14Ρ
14
Green β large heatsink 50Ρ
25
For a price of 1$ you can greatly improve temperature of Raspberry Pi 3 β by 8 degrees in idle state and by 13 degrees under moderate load.