spence4 said:
Minihack, I hate to go back-to-back on you like this, but I just saw these two units which look very similar to the cool jag, but they have a chart. I don't know what it means but you might.
Copper
http://www.dynatron-corp.com/en/product ... d=190&in=0
Aluminum
http://www.dynatron-corp.com/en/product ... d=225&in=0
And one more
The SuperMicro SNK-P0046P
Be interested to know your thoughts... to me they all look the same
No expert, but CFM is cubic feet per minute and is a measure of airflow.
Now the Noctua 80mm base fan on lowest (silent) settings gives (according to this:
http://www.quietpc.com/products/80mmfans/nf-r8 ) 15.3 cfm. relating that to the chart for the copper heatsink you get a thermal resistance of about 0.287 degrees per watt and so for a 65W TDP full out you would get a heatsink temperature of around 18 degrees C + ambient = perhaps 40 degrees. Then assuming 5cfm you have about 25 degrees + ambient (47 degrees) max. There is no chart for zero cfm, and I have no idea what the cfm is for convection via the Cube "chimney" effect. It does though when you look at the chart and put in the numbers show that these heatsinks seem to be good.
For the Ali heatsink 15cfm gives around .36 degrees per watt, so that means 65 x .36 = 24C + ambient when using the Noctua fan slow speed. Again, no figure for zero cfm, but lowest cfm quoted is 10 which has degrees per watt of .448 which is basically about 30c + ambient for full wattage.
These seem good heatsinks that with minimal airflow across them will perform well. In terms of the noise of the Noctua fan I link (other quiet fans are available!!!) just look at the spec.s - 7db is
below background noise in a dead quiet room. Honestly, the same as in my own Cube you will NOT hear these fans at minimum settings. The copper will perform best but weigh a tonne. The Ally one is less good, but still excellent enough - realistically you will never go full TDP except briefly and even then you will still be running cool.
Note: If you have no base fan at all, then of course "ambient" temp becomes the temp of the heatsink, so of course temperatures will build over time to above what they may seem to be in my simple explanation above. You always need "some" airflow.