Frostythedadman, over at LE, tested a Chunk heatsink and this is his post and review of the little beasty :
The boilling water test at Home
I Put the Chunk in a small pot of water and brought it to a Hard boil, Off to the side I had a Coffee cup with 1 cup of water in it, the temp of the water in the cup was 68 deg F / 20 Deg C, The temp of the boiling water was greater then 300 Deg F / 148.8 Deg C, at that point I took the Chunk out and put it in the cup of room temp water and recorded the temp change of the water and how long it took to equalize, It only took 2 seconds and the Temp change of the water only changed by a little less then 6 deg F / 3.3 Deg C, The CHUNK disapated 226 Deg F / 125.5 Deg C in 2 seconds WOW
The free air test
I heated that same pot of water with the Chunk in it again to 250 Deg F / 121.1 Deg C, Then I put it on a wire rack and in a matter of aprox 50 seconds it was down to 84 Deg F / 24.4 Deg C, So The Chunk Disapated 166 Deg F / 92.2 Deg C in under 1 Min. Thats 3.3 Deg F / 1.83 Deg Per second WOW
The Lab Test
We put the Chunk on a heat controled surface and set it for 1.5 Watt and after 2 hours the temp of the Chunk only increased in temp by 11.5 Deg C /10.7 Deg F over room temp WoW
thats better then the transister heat sinks from Thermalloy that I have been using. So I am figuring that The Chunk can handle Power levels greater then 1 WATT I would guesstomate It could handle a 2.5 Watt Diode with no problem.
so far 5 Thumbs up.
Next is to try it with a 1.6 Watt 808 nm C mount and then my 2 Watt 808 nm C mount