What'd happened when heatsink reaches it's peak C/W
 

I was able to finish this test from the heat wave in the last two days.

Background:

Using identical system setup.

1) HSF max out at 43C under load at 21C ambient.
2) The same HSF max out 52C at 25C ambient.
3) The same HSF max out 57C at 30C ambient

A 4C rise in ambient resulted to 9C rise in CPU temp.
A 9C rise in ambient resulted to 12C rise in CPU temp.

The base line was 22C rise from ambient. Yet, when ambient temp rises; the 22C Delta is not linear.

At 25C ambient the delta is 27C
At 30C ambient the delta is 27C also.

Conclusion:

C/W is relative to a given wattage and it may not be linear due to other variables other than then heatsink, such as rise in case temp, PSU power loss from higher temp etc.

This leads me to believe the same applies to W/C and Vapor Chill.

For overclockers; the best solution to sustain your highly overclocked rig is to invest in the construction of a restaurant type freezer. They normally measure 3m x 6m with temp kept at about 1-2 C. Remember it could house more than 4-6 systems. Therefore, the cost per PC unit is definetely non-linear. Proper clothing is not included.;)

that's why I like to do heatsink reviews, all in one session with ~1 °C max variation of the roomtemp :)

I'm pretty impressed with the Scythe Samurai here, with a room temp of 21°C it sits at 58°C under load; open case
at room temp of 26°C it is at... 58°C

I have to mention though that loads temps are reached through f@h so it might be off quite a bit

cpu is 2.4 "c" @ 3.2

Artic Cooling 2L could achieve better C/W than it's current configuration. Hence, the CV could drop a whopping 9.5C.

The same applies to copper base Stock Intel. A maximum C/W is achieved when a bigger or faster or higher CFM fan could no longer reduce CPU temp.

But, I still say investing on a restaurant fridge will give people more bang for the buck.:^D