that was close

[ethiko]

i built a water block. very simple one: an old AMD heat-sink a pump i used to use for a fish tank and a piece of glass. assembles in minutes and needs 24 hrs for the silicon sealant to dry. no leaking what so ever.



i'm supposed to get a radiator in a few days but i lack the patience so i decided to give the "system" a try.

i filled the reservoir with ice and a little water just so that the pump would start pumping !!

my intel q8300 ran at 3.6ghz without even messing around with voltages or anything just set the fsb to 480

it ran cold... at full load for 10 min it didn't get past 39C...

i restarted the PC but it refused to boot... just black screen of nothing.

i freaked out removed the block and took the CPU out to find a tiny drop of water from condensation on the edge of the CPU and because of the capillary effect the water crawled between the board and the metal surface of the CPU.

i dried it aggressively with a hair dryer and put it back in with the old zalman air cooling heat sink i usually use (which sucks by the way) the system went back to normal i reset the bios settings to default and called it a day.


my question though: is this going to happen, i mean the condensation thing when i use ambient temperature water, with the radiator ?

am i going to get that kind of performance out of the cpu 3.6ghz?? and still run cool ??



that is a very simple design i made for testing if anyone likes to see other more sophisticated water blocks just ask i'll post pics with dimensions and discriptions how to make them.





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[musicfan]

I could be wrong but suspect condensation was when you went sub-ambient temporarily with ice. Condensation is caused by going below dew-point is my understanding (look at the little graph). Hopefully that won't bother you with ambient temperatures closer to room temperatures. I don't know how to predict your performance but please share your results. Congratulations on the creative design.

[ethiko]

i'm working on another design (working means waiting for the silicone sealant to dry) it's very simple but it's made in a way to eliminate condensation ... over the internet when you search for water blocks, fancy designs that need heavy machinery and workshops pop up... while in fact an old cpu heat-sink or even a bios heat-sink, a piece of clear glass a knife and some silicone is all you need. though i design fancy water blocks, i prefer practical simple designs.

musicfan when this one is done i'll post pics and some data.


how much thermal energy would a cpu produce? in joules? i searched over the internet but found nothing






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[apw63]

How to convert watts to joules

Andy

[Mr.Scott]

it's very simple but it's made in a way to eliminate condensation

Subbed.
There is no way to eliminate condensation when going sub-ambient unless you can control the dewpoint.

[Mr.PACO]

Very interesting.
As I run ice/water on a regular basis and am constantly fighting condensation no matter what I do.
Look forward to seeing your results.

[ethiko]

Originally Posted by Mr.Scott

Subbed.
There is no way to eliminate condensation when going sub-ambient unless you can control the dewpoint.

or... unless you control the temperature of the surface

but first you can go sub-ambient and still no condensation. dew point can be less than ambient temperature in fact it cant be higher or vapor will start to condensate thus lowering the dew point to equal or less than ambient temp.

with the right insulation and maybe a small fan i might be able to stop condensation i'll give it a try.

[Mr.Scott]

With a fan and proper insulation you might be able to control condensation to an extent, pending the conditions in your area, but you'll never stop it completely. Proper insulation of your hardware is a must for going sub ambient. Condensation is almost a guaranty at some point.
I'm no stranger to sub-ambient benching, so unless you're coming up with something revolutionary, condensation is eminent at some point. Best to prep your hardware properly or it won't survive. You barely scratched the surface in your first attempt and see what happened then?

[ethiko]

Originally Posted by Mr.Scott

With a fan and proper insulation you might be able to control condensation to an extent, pending the conditions in your area, but you'll never stop it completely. Proper insulation of your hardware is a must for going sub ambient. Condensation is almost a guaranty at some point.
I'm no stranger to sub-ambient benching, so unless you're coming up with something revolutionary, condensation is eminent at some point. Best to prep your hardware properly or it won't survive. You barely scratched the surface in your first attempt and see what happened then?

well... i'm always glad to learn from people with experience


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Additional Comment:

Originally Posted by apw63

How to convert watts to joules

Andy

that's not what i meant...

part of the energy a cpu consumes gets converted to thermal energy that can be measured in watts... lets say a Pentium 4 3ghz full load how many watts of heat does it produce ?

i couldn't find this piece of info any where on the internet

[apw63]

Originally Posted by ethiko

that's not what i meant...

part of the energy a cpu consumes gets converted to thermal energy that can be measured in watts... lets say a Pentium 4 3ghz full load how many watts of heat does it produce ?

i couldn't find this piece of info any where on the internet

You are asking a efficiency question. I'm not sure how to calculate how much energy goes to work, and how much goes to heat loss.

These links if you have not already read could be of interest to you.

CPU power dissipation
Junction temperature
Thermal design power

Andy

[ethiko]

Originally Posted by apw63

You are asking a efficiency question. I'm not sure how to calculate how much energy goes to work, and how much goes to heat loss.

These links if you have not already read could be of interest to you.

CPU power dissipation
Junction temperature
Thermal design power

Andy

thanks a lot

The thermal design power (TDP), sometimes called thermal design point, refers to the maximum amount of power the cooling system in a computer is required to dissipate

Core 2 Quad Q8300 Yorkfield (45 nm) 2.5 GHz 95 W

i always thought that TDP was the power a cpu needs from the power supply... maybe, and i'm no expert, all the power consumed by a cpu or most of it is converted to thermal energy, that could make sense since a cpu doesn't produce light or mechanical movement like a motor, the electricity that goes inside moves electrons around thus producing alot of heat that is most of the electrical energy... just maybe


but whats important is that a q8300 at 2.5ghz full load produces approx 95 joules of thermal energy per second that means it can melt 1000 g of ice at 0C in approx one hour