Originally posted by: Elias824
well I doubt that it would be much of an issue as long as the test it in a reasonable sized room with decent airflow, I dont think they would have much of a difference in room temps.
The problem is "much of a difference" can mean several rank levels on the charts. If you look at the
latest chart (for load temps) here at AT, look at how many HSFs are in the 38-40C range. If any one of those was hit with an extra 2C of ambient (or visa-versa) it could move pretty far on it's 'percieved' cooling value (note that a chart like this might already give the 'perception' that, for example, the Thermaltake MaxOrb cools better than the Noctua NH-U12F with stock fan under this test setup, because it's higher up on the chart - even though the temps are the same).
Then you have the cumulative affects of (for example) 'most' being tested at 25C ambient, but say maybe one was tested at 23C and another was tested at 27C - now we're talking about a 4C delta...
Finally, at least one person has
looked into how ambient temps affect cpu temps and at least with his setup, he was consistantly seeing a 1:2 ratio. ie. Every 1C of ambient, was adding 2C to his cpu temps (this was on a Quad, so I don't know if the same holds true for Duos). So if this is true, we're talking about as much as an 8C swing.
So, all the sudden "not much of a difference" has (potentially) turned into an 8C difference - starting with the Ultra 120 Extreme at the top of AT's latest chart at 32C, you can include 15 other HSF configurations within an 8C swing of there

.
I'm fairly
certain that this is not the case for this chart, but my point is that a few C of ambient can make a huge difference, when you already have to take other things into account, like the TIM being used and it's application, the amount of mounting pressure achieved for the test, case fans on or off, cpu used in the test and at what voltages, application used to create load conditions, etc.