peter wrote:

here is a little article ( a bit old maybe but still true) on heat and CPU
life span...it includes info on CPU Delta T

http://www.overclockers.com/tips30/

Once upon a time I did a small power test...I had been running my systems
24/7 so for one month I turned them on only when they were in use ...I
saved just under 3.00 per month in power cost....That is for 2 computers.
I believe in the cooler the better...and a small fan.or 3 small 120mm fans
in my case do not amount to a huge amount of power consumption.
These are the fans that I use....note the power
http://www.scythe-usa.com/product/ac...ex_detail.html


Thanks, very good article. The CPU Delta T is an input that I can change in
my bios, I don't think it is the same one as he is talking about. But the I
like the article. Sounds like the Delta T in the article is Running Temp
minus Ambient Temp.

I still have no idea what the *input* "CPU Delta T" in the bios actually
does for me.

For any given heat sink with a variable speed fan,

delta T(1) = Temp(100% load, 100%fan) - Temp(idle, 100%fan)
delta T(2) = Temp(100% load, 100%fan) - Temp(idle, 50%fan)

delta T(2) delta T(1)

Reduces thermal cycling Delta T between idle and full load (is good), but
increase Idle temperature (is very bad, very very bad for a 24/7 idling
computer)

I'm not a gamer, but when I run some of my own software it runs for five to
six hours. That's only one thermal cycle, cruising the Internet is much
worst than gaming or running one long program. A game is only one thermal
cycle too.

Ok, I'll quite messing with the variable fan and run it at 100%. Even though
the delta T from idle to 100% load will be higher. The lower idle temp with
the fan at 100% is better.

So why did they go to the trouble of putting a variable speed fan on my
motherboard?