Desmond said:
It is so hot here this summer that my computer crashes when it gets hot.
I was looking into water cooled pc cases. Is it safe to buy a kit. Also the
prices vary from £199 to £1,400.
http://www.watercoolinguk.co.uk/p/W...2-240-Watercooled-Case-Black--Blue_35292.html
I am not sure about the options here. Do I NEED to pick one or can I just
transfer mother board and other things into the case. Any help would be great.
Desmond.
That particular product, looks to be a combination of two products.
A CM-690 Version II, is a computer case. Coolermaster makes a number
of minor variations.
http://images17.newegg.com/is/image/newegg/11-119-259-Z05?$S640W$
The "240" in the title, could be referring to one of these kits.
It has a water block for the CPU, and a radiator that fits near the
top of the computer case. The radiator has exhaust fans, to move
the heat out into the room.
"COOLER MASTER Eisberg 240L Prestige"
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103184
Your web site doesn't go into enough detail, for me to verify those
are the box contents.
*******
I wouldn't buy something like that, without first understanding
why the current cooling solution is not working.
Air cooling, is a two stage process. CPU to case air, is handled
by the CPU cooler and CPU fan assembly. That transfers the CPU heat,
into the case air, and makes a "warm cloud" around the CPU.
To move the warm cloud, you need an air intake vent (near the front),
and an exhaust fan (near the back). That causes a constant flow of
air through the case, and moves the "warm cloud" out of the computer.
You can trade off the two cooling subsystems. You could use a loud
back fan, and a quiet CPU fan. Or a loud CPU fan and a quiet back fan.
In other words, both parts have their own delta_T to contribute to
the final CPU temperature. If you're using the finest cooler for
the CPU, that money can buy, and the CPU still isn't cool enough,
it means the exhaust fan on the back is not enough.
A "well cooled case", has a 7C to 10C temp rise above room temp.
Say the room is 25C. Then if your motherboard has a surface mount
thermistor, it should register 35C or less. That tells you the
exhaust fan on the back is doing its job. On my previous computer
case, I had to remove some plastic trim on the front of the case,
to get sufficient air intake cross-section, to support the volume
the exhaust fan was moving. (I was getting the vacuum cleaner sound,
when the side panel was placed on the case. More vent in the front,
eased the vacuum cleaner effect.)
The CPU cooler is rated by "theta_R". (Only Zalman will tell us the
value, and most manufacturers won't admit the value, as it makes
shopping for the best one, too easy.)
Let's work a typical example, using our 25C room, and 35C internal
case air temperature.
The cooler that comes with the CPU, has a theta_R of 0.33C/W.
Say the processor is 100W, just to make the math simple.
0.33C/W * 100W = 33C. 35C case air, plus a 33C delta_T to
the CPU inside, gives a CPU lid running at 68C. This is a bit
on the warm side.
If I switch over to an enthusiast air cooler, perhaps it has
a theta_R of 0.15C/W. Now the delta_T is 15C, and the CPU is
35C+15C = 50C. This is below 65C (for certain AMD processors),
and I'm happy.
Notice the two contributions. The rear fan made things 10C warmer.
The CPU cooler made things 15C warmer. There isn't much room left
to improve either of them now. I would need a very loud rear
fan to get below 10C delta. And the CPU cooler, it's hard to
find something below 0.15C/W. Maybe I can find a 0.11 or 0.12 one.
Some of the coolers are so large, they prevent all the DIMMs from
being installed, so be careful what you wish for.
Based on these examples, measure your CPU temperature, internal
case air temperature (use a glass thermometer), and room air
temperature. Compute your delta_T values, and see if something
isn't obviously out of whack.
When you fit the CPU cooler:
1) Check that it is fully seated. I had one cooler that sat
at an angle, because the heatsink was the wrong shape. It took
a solid half hour of filing in my bench vice, to fix it. As
another example of an oddity, on Intel Core2, the top of the
processor is convex, while the CPU cooler is flat. No, I don't
recommend lapping it. The convex shape is the result of the
soldering operation they use, to affix the top.
2) If using thermal paste, make sure the gap between CPU cooler and
CPU, has just a tiny bit of paste oozing out of the gap. That helps
prove you used enough. If you didn't use any thermal paste, and
there was no other thermal interface material (TIM) present, then
that is your problem right there. The CPU is going to throttle,
if there isn't some paste present.
3) Make sure the heatsink fastener is secure. On AMD, a certain brand
of cooler is known to snap off the plastic tab on the side of the
processor socket, leaving the cooler dangling loose, and causing
an overheat. If the fastener pulls on the plastic socket, inspect
it regularly to make sure it is still holding
If you're overclocking, I can see the attraction of a water cooling
system. If you're running stock clocks, then you should be able to
scrape by with air cooling. Some overclocking efforts, dissipate
200W at the processor, which is a bit much for a cheap air cooler.
To work out the required CFM of the rear fan, the cabinet cooling equation...
CFM = 3.16 * Watts / Delta_T_degrees_F
Here, watts would be the total watts of video card plus CPU plus
hard drives and so on. That could be a couple hundred watts. If the
video card vents out the back, a fair portion of the power is not
to be counted. If you do that math, and get 35 CFM, that's an
"ordinary" fan and not obnoxious. If the math works out to 100CFM,
you'd either need a very large fan (a case with a 220mm fan),
or be prepared for a deafening roar. I have a fan that will do
110CFM or so, and I have to keep it turned down. I'd have to leave
the room, if I fed the fan the full 12V. The fan in that case, is
37.5mm thick and thicker than a standard fan. And I think it draws
around 1 ampere of current (so it's not a good idea to run it
off a motherboard header). That's an example of an extreme. And
you don't really want to do that. A number of Dells use fans like
that, but normally the fan control is turned down on those as well.
Only under a failure, does the Dell fan start to wail.
But at least there is a cabinet cooling equation. If the computer case
air seems really warm, and you have a good idea of the total DC power
being used in the box, then you have the ingredients to figure
out the fan CFM (cubic feet per minute) needed. I'm not skilled
enough in the maths of CFMs, to tell you what happens when
there are seven fans, some pushing and some pulling
That
is why I like to start with a simplistic cooling system, so
I can easily relate to the cabinet equation.
HTH,
Paul