Noise of dust temperature estimates, δT, as a function of the radius in an externally heated 1 M_⊙ model cloud. Results are shown for the CRT program (solid lines) and the DIES program (dashed lines), with the run times quoted in the legend. Results are shown also for weighted runs, when photon packages are targeted more towards the model centre (“CRT-W“ and “DIES-W”, respectively). The noise has been estimated from the standard deviation between 50 runs.