The copyright date for the .PDF is 2003, but for some reason PCP&C
still has it posted at their website:
http://pcpowercooling.com/pdf/insidestory.pdf
The-other, now prominent PDF is relatively new, only came
out after nVidia/SLI specs (see bottom of it). This 40C
rating was indeed used for several years and only more
recently was it increased to 50C. There's that quote on it
from April 2005 too... not sure what in the world UCLAN is
trying to claim so far as "as far back as can be remembered"
since it wasnt' there 18 months ago.
I think it's funny that they say, "Turbo-Cool 510 derating spec:
full-load @ 40C, decrease to 90% load @ 50C", and for the 550W Enermax,
"full-load @ 25C, decrease to NO LOAD [caps mine] @ 70C."
The sad part is that many people look unfavorably on Turbo
Cools citing noise levels but fail to recognize that it's
merely because they actually have the airflow to accomdate
510W, even though able to do better at the lower airflow
rates of many other alternatives.
It's somewhat incredible though, how some manufacturers are
so greedy that they can't even manage to put $5 more into
heatsinks, fan and capacitors- in those 3 areas alone would
most supplies be vastly improved.