I think that they were trying to develop a measure for how fast heat was removed from the CPU. The really important figure is maximum CPU temperature at maximum usage, but that will change with room temperature, which is why they measured the time to drop the temperature from max temp at maximum usage to minimum temp at cpu idle.

Absolutely! There are definitely two separate heat transfer processes that are taking place here:

1. from processor to heat sink
2. from heat sink to environment

This article addresses the second and effectively says two things in my opinion:

1. air flow is important i.e allowing cool air to enter the PC case and taking hot air out of the case in such a way, that the cool air gets to the "hot spots" and once heated, gets pulled out of the case
2 the turbulence created by two many fans causes two problems:

a) mixes hot with cool air - so you end up with warm air (which in turn does not allow heat sinks to cool fast as the amount of heat transferred is proportional to, but not only, the difference in temperature between the heat sink and the surrounding air)
b) turbulence creates noise = energy = heat. So the overall effect is that turbulence warms the air within the case (not considerably, but a degree or so), not to mention that the air being blasted into the case is heated by the fans themselves (fans also produce heat and the airflow through them, cool the fans down, but transfer the heat into the case - one more reason to suck out rather than blow in)

With all that being said, the whole article really applies to a standard PC that does not have too many mods - extra cards, discs etc.
I have followed their advice and not gone for any fancy heat sinks for my PCs and have achieved the following with just one additional extractor fan at rear of case:

Intel P4 2GHz
CPU temp: 39 C
Chipset: 41 C
hard disc: 32 C


AMD XP 1,8GHz
CPU temp: 45 C
Chipset: 29 C
hard disc: 35 C

running 24/7 - both maxed out at 100%
Ambient temp = 21 C

... or maybe this isn't good - what are you running?

I usually get up before the alarm goes off at 6:00am. This morning I this horribly noise woke me up - so I stuck my right foot out from under the duvet to switch the alarm clock off ... and to my surprise the noise did not go away.

Woke up straight away as you can all imagine. Looked at the clock. It gave me a Garfield grin 5:30 as if to say "you get up, but I am going back to sleep"...... so I leapt out of bed ran to my office (the room next door) and ...... the CPU fan on my PC had just run itself aground!

Shut the system down, pulled out a can of WD 40, sprayed the fan, wiped off the excess liquid and switched the PC back on - fired up straight away and the fan was fine. Measured it, got onto the net to buy a new one and...... couldn't find a 70mm fan - Why on earth had someone put a 70mm fan onto the CPU cooler? I found 50, 60, 80, 92 etc.... but no 70. So I decided it is time to buy a complete heat sink.

Bought the new one, pulled the old one out and the was no processor in the socket! - It was stuck to the old heat sink..... .....to cut a long story short, I have ended up with an extremely quiet "Artic Freezer" . The temp on the CPU is hovering around 35C having pushed the processor speed up from 2Ghz to 2,3GHz running the wcg agent full blast ... and I cannot tell if the PC is on or not as it is so quiet!.... Quite amazing!


Nice and warm here today. Have a good weekend