i have been tinkering with my xigmatek hdt s-963 as its a good heatsink but it doesnt rival the big boys and have found that quite a lot of air escapes out the sides and with the stock ~40 cfm fan thats a lot of air
so i decided to do somthing about it to see if redirecting this lost air would help temps
core temp was used for temp taking
cpu used was my e2180 @2.9 1.41vcore idle 1.39 load
idle with fins open was ~ 32c (no pic)
idle with fins taped was 28~29c
load with fins open was ~52c
load with fins closed was an impressive
testing was done with case side of hsf mounted horizontally blowing air to back fan with a 120mm fan blowing air in to it (pics on request)
hopes this helps all you extreme Air OCers with hdt s1283s trues etc.
EDIT: continued load of almost 1/2 hour with side off or on yields 46c max