Water is life, but one
cannot live without air either. Our myth chaser clarifies which element is
better for cooling the PC.
The myth
water is better suited than air to cool a processor. Water has a higher heat
capacity and thermal conductivity. Hence, water cooling can take away the CPU
heat in a more effective manner. This way, the inner parts of the computer heat
up less.
Water cooling is the
first choice for PC
The truth
physically, the assumption that water is better for cooling is correct without
doubt. When compared to air, the considerably higher heat capacity (i.e., the
amount of heat that can be assimilated per kilogram) and thermal conductivity
(how quickly the heat is taken away) of water ensures considerably better
dissipation of energy. This is why water is also used as a cooling agent in
cars or nuclear power stations. The effective stemming of high generation of
heat is important here.
This is
also important in a PC, but completely different factors are taken into account
here - depending on what one wants to achieve by cooling the PC. Water cooling
is the first choice if the focus is on maximum overclocking of the CPU: in the
test, we could overclock an AMD FX-8150 on the ASUS Crosshair V Formula
mainboard to 4.8GHz with the help of an air cooler. The temperature of the CPU
increased up to 70 °C. With water cooling the eight-core CPU functioned with a
much lower temperature of 65° C with the same clocking - and could also be
overclocked to more than 5.1 GHz.
if you don't want to test the limits of
your silicon chip, air cooling would be a better option for you.
However, if
you don't want to test the limits of your silicon chip, air cooling would be a
better option for you. In normal operation, the difference in temperatures in
case of water or air cooling is not very distinct, the operating noise during
water cooling is not lower and finally even the liquid is cooled with a
radiator with fans. Besides, the water pump generates noise (air: 1.8 sones,
water: 2.0 sones). Higher acquisition costs and much more work in terms of
installing the water cooling unit are involved - even if it is already integrated
in the housing as in case of Thermaltake Level 10 GT LCS. What's more, using
water can also be risky: if there is no air draft in the housing, the voltage
transformers or capacitors of a component on the mainboard can get overheated
and hence break down. Secondly, the water cooling device can leak - and result
in a short circuit due to the high conductivity of water. Therefore, if you
don't need maximum output, air cooling is a more suitable option.
Water Vs Air - ranking
To find out
which cooling agent is better, let us compare air and water in various
categories. The air wins in the end!
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Water
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Air
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Ranking!
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Physical
comparison values
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Heat
capacity
|
4,18
kJ/kg K
|
1,00
kJ/kg K
|
1:0
|
|
Heat
conductivity (at 20° C)
|
0,597
w/(m K)
|
0,0261
w/(m K)
|
2:0
|
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Heat
transfer coefficient
|
Up to 700
W/(m2 K)
|
Up to 10
W/(m2K)
|
3:0
|
|
Viscosity
(at 20“ C)
|
1,0 mPa s
|
0,0182
mPa s
|
3:1
|
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Freezing
point
|
0,00 °c
|
-218,3 °c
|
3:2
|
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Boiling
point
|
99,97 °c
|
-182,9 °c
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4:2
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Comparison
values for cooling in pc water vs air
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Cooling
costs
|
Approx RM
1,800
|
Approx
RM420
|
4:3
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Complexity
of installation
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High
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Low
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4:4
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Risk
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Leakage
|
Hardly
any
|
4:5
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Operating
noise
|
2,0 Sone
|
1,8 Sone
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4:6
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CPU
temp.; normal clocking
|
40 °C
|
40 °C
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5:7
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CPU
temp.; overclocking (4.6 GHz)
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65 °C
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70 ”C
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6:7
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Final
result
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6:7
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CPU - temperature comparison
For a computer operating with
normal CPU clocking, there is no difference between water and air cooling
For a
computer operating with normal CPU clocking, there is no difference between
water and air cooling. Water cools slightly better only if the processor is
overclocked to a great extent.
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