I do consider core i5-3570K. :)
I just want to have fun of overclocking,
I will monitor the Temperature.

I think I must buy a good VGA card for Battlefield 3. :D

Here is our Malaysia's PC components' price.
http://www.asashi.com.my/index.asp

Some people suggest just do not close one side of the casing cover,
put a small fan in front of it to blow,
surely the temperature will be low,
if you do this in air-cond room,
that would be perfect,

You can then overclock to 5 or 6 GHz. :D :D :)

I think this is a genius's suggestion.

You think that because you haven't done the math, because you probably don't know the math. Each stage of die-->plastic-->heatsink paste-->heatsink-->air fan assisted at a specified speed has a thermal resistance at a specific speed has a thermal resistance in degrees C per watt. The total is R1+R2...etc.

You need to start with the highest watts in the die, and from the highest ambient temperature, and then work out the total degrees C per watt. so if it's 1.5 degrees C per watt, and the thing uses 80 watts, thats 120 degrees C above ambient. You are trying to avoid some nebulous spot where temperature differences in the die cause cracks, much like pouring cold water into a hot glass bowl

Every motherboard design out is flat up against at least one specified design limit. The room for overclocking is in the 'safety margin' above those design limits before the device stops working. That's a tiny area.

I'm unsubscribing from this thread because you don't seem to accept or understand the answers to the question you asked.

This is not a genius suggestion. This is a really dumb suggestion. You still don't understand that you can't cheat the laws of physics.
It is your own hardware, fry it if you want, but don't whine here about it, we warned you and you decided not to hear or even learn anything about overclocking.
Since you refuse to learn about overclocking this whole thread is pointless, especially as you now start to give absolutely dangerous advices.

Ask yourself a question: If it is so easy to get to 5-6 GHz, why isn't Intel selling these CPUs for that range with a decent cooling system? They really could make a lot of money with it.
The answer is really simple: They know their CPUs and they know that it isn't possible. But don't bother to think about the advices from people that have done already successfull overclocks, just try it and fry your hardware.

Of course I will not drive my car up to its maximum speed, it will be unstable and easily out of control and cause accident.
This is common sense.
:D

Anyway, I do test before, open the casing cover, blowing it with fan,
from the Everest software, I can see that the mobo and cpu's temperatures dropping lower.

This is not against law of physics,
this is actually law of physics,
blowing with air improve heat dissipation by convection.

Newton's law of cooling.
heat loss is proportional to heat transfer coefficient and temperature gradient.

So and where is your math proving that this will enable you to overclock to 5-6 GHz?

The 'desktop fan blowing in, with the side removed' trick? LMAO. Seriously. Its a very old trick.

That will NOT increase max sane overclock from 4.something Ghz to 5GHz or 6GHz.

Overclocking is nothing like driving a car at maximum speed. Not even close.

You wont (normally) blow your car up while waiting at the lights. I've seen overclocked CPUs blow while idling.

Yes, moving more air over the heatsink will lower temps, but blowing more air will not improve the CPU-> heatspeader-> thermal paste-> heatsink thermal transfer. Considering that you were saying stuff about I7-3XXXs having a max temp iof 105C, your temps could be 'lower' with a fan pointing into the case, but still 'way to high for the CPU to handle'.

From experience I can say that a well thought out airflow path, and trying to improve the thermal transfer can work better than just 'blow as much air as possible into the case'.

You need to experiment it,
first step is to enhance the cooling mechanism.

I can't tell you until I had done it. :D

Where will the heat go?
Into the ambient air, right?
If your casing is closed, though it has another fan for ventilation,
but there are still air trapped inside the casing and rising in temperature due to the heat from the CPU and motherboard.

So, higher ambient temperature in the casing will hamper heat loss.

Open up the CPU casing,
enhance air flow out of the box, your heat sink will always has a temperature gradient towards your ambiance.

This will help in its efficiency of cooling.

Same theory applies to water cooling,
it is like the cooling system of your car engine, the water circulation and radiator blown by a fan.

If you open up the case you are destroying a sanely planned airflow because you are removing the tunnels through which the air flows. A properly set up cooling system in a case with a proper designed airflow will always be better than just opening the case.
May I ask you which CPU coolers and which cases you have used to test your theories? Are they in any way related to the equipment an overclocker would use?

I find it funny that you now try to teach your theories to people who actually have experiences in overclocking (and running stable overclocks).
If you know all that already , why did you have to open this thread in the first place again?

My machine is not for overclocking,
I only noticed the temperature difference before and after opening the casing.

What airflow tunnel are you talking about? It is irrelevant.

No matter it is fan or water cooling,
heat is to be carried away from the CPU's top surface to the ambient.
the fin and so on are for conduction as well as convection (more fins more areas to dissipate heat),
heat accentually is to be thrown away to ambiance.

It is the thermal conductivity of the heat sink materials,
the total area exposed to air,
the heat transfer coefficient,
the Temperature Gradient that determine the rate of heat loss.

Higher temperature gradient will increase its efficiency.

The CPU has its material property of heat capacity,
how much heat it produces will increase its temperature,
this creates temperature gradient with the ambiance,
even without fan, natural cooling will occur too.

So, our fan or water cooling,
is Forced Convection.

So you don't know what is meant and therefore it must be irrelevant?
Talking to you is like talking to a wall, a waste of time and useless at all. I decided to not answer anymore at all in your threads until your posting style is on a level that almost all other members here have been able to reach. Except if I have to in my function as moderator, of course.

Look, before you do anything, take your stock system and run a prime 95 torture test on it. Not for 10 minutes. Try about 5 hours. You will probably be surprised and humbled. If you exceed the design temp your system isn't stable and you shouldn't even think about overclocking.
A system that is not stable under any condition is not stable, and therefore not properly overclocked. The definition of a stable system is a system in which outputs are bounded under all conditions.
If your temperature continues to rise, you need better cooling. If you are above the design temp you need better cooling, and while you're system may be stable you are playing with fire.