Just using a heat source does not tell you how a heatsink will work inside a case on an actual working PC.
Exactly, because the point of the experiment is to test heatsink, not your case.
We don't believe in that type of testing and it introduces far too many variables.
Now you're trying to tell us that white is black. Are you a politician or what?
Here are some random variables present in real world setup:
- unknown and uncontrollable power output of a real CPU
- low precision of on-die thermal diode
- matching diode output to program used to read values
- airflow restrictions imposed by particular case, PSU and motherboard setup
- external airflow introduced by PSU and case fans
- air temperature affected by other components preheating it.
- heat removed via motherboard conduction
Synthetic heater is a way to get rid of those variables.
In theory it is not a bad idea, but in practice it just isn't realistic.
It's as realistic as it can get, if one wants to test CPU heatsinks.
If you want to test entire rigs, sure, your methodology is superior. Just please, don't call it heatsink test, because it isn't one.
I can design a setup where passive HR-01 will outperform top active cooler. It's very simple, just block active cooler's fan with PSU wall and let case fans do sideways flow. What would it prove? That it's one very special rig, nothing more.
Less extreme example: Does your case have so called "prescott duct" and fan? Mine has, so tower coolers in my case will never be a match for a top-down cooler force fed with fresh air by a dedicated 120mm fan.
I know that building a proper test stand takes time, effort and money. I understand that you're unwilling to do it, and that's fine.
It's your test, not mine. I'm not trying to force you into anything.
Just don't try to tell us that your method takes away randomness, when it introduces it. Because that's plain lie.
Only thing that synthetic might not replicate exactly is the uneven heat distribution pattern of the CPU (which is questionable difference due to heat spreaders in modern CPUs). However, it's very simple to have many differently sized heaters (as heater die is one of the cheapest components) AND to test if heater size do actually have any influence on performance.
We can figure out, you say. How tests done on i7 relate to, let's say, Athlon 2650e? (15W TDP) How test results from forward-to-backward flow relate to top-down case?
Well, I can't figure out. Call me stupid.