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1/2 or 3/8? final thoughts please.

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Jun 19, 2001
I got my heater core tonight from my local autoparts store. I went through the book and found it by dimensions. I am going to get a waterblock and pump now. I want everyone's final thought on going with 1/2 inch tubing or 3/8. I can get all my stuff both ways. Is 1/2 overkill? Is it good if I add a video and chipset block? Or is 3/8 better to keep up the pressure? Please give me your opinion, I'm looking for a good setup.
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It really does not matter using 1/2 or 3/8 will not effect your temps at all. It all depends on whats more convienent for you. I personally use 1/2 becuase oh well I don't know I just do but whatever you pick should be fine. In fact if you go with 3/8 silicone it will be able to fit over all 3/8 fittings and most 1/2 fittings so this would be a good way to go.
As long as you can get all your components the same diameter, you are better off going with the 1/2". Most problems occur with the mix'n'match approach, which creates flow bottlenecks. As long as you get a quality higher gpm pump, you'll be fine.
The most important factor is water velocity through the water block. That is why turbulence is important. The faster the water flows over the water block's internal surfaces, the more cooling effect you get. That's why tubulence is important. Turbulent water has more velocity over the metal's surface than laminar flow does at the same flow rate (gallons/hour). So, what I like to do is have everything in your system 1/2 inch, except use a water block DESIGNED for 3/8 inch (like the Gemini low flow). In the old days, they used to do strip mining with water cannons. Water cannons were simply gravity fed, with the water going through progressively smaller pipes, then through a nozzle. This would produce very high water velocities that they would spray against a hill side, and this would wash away the soil very rapidly. Same principle here. Everything 1/2 inch, then step it down to 3/8 through the water block. This produces faster water flow through the water block. It's like putting your thumb over the end of the garden hose to get a higher velocity stream of water.

Doesnt that make the pump work harder in turn making the pump work harder, building more heat?
Ok, my personal opinion: 1/2" tubing can't be any worse than 3/8". BUT...I can see potential for 3/8" being worse than 1/2" with possibilities of flow restriction.

As for the pump havig to work harder, I would think it would need to work harder to push water through the smaller tubes.

Also, if your system is completely closed, there shouldn't be a problem with the volume of water it has to move because the water flowing down works as a siphon to pull up the water flowing up.

I say 1/2" if you don't have to worry about the extra bit of room it will take up.
In the end, it wont really matter for your CPU temps IF
you have "normal" water cooling components. What you
gain by 3/8 inch stuff is flexibility. I mean you wont have
to fight the water lines in your case as much.
Ok guys thanks for all the input. I will go with 1/2 because it doean't look like there is a down side to it and I have an enormus case.