1/2" or 3/8" Tubing for WC setup?

[Alik AlRahim]

While I was originally writing this post my computer overheated and died (again) so I decided it would be a decent idea to go with the Bong Nuclear Tower (http://www.overclockers.com/articles389/) setup that was on here a few months ago. (I'm thinking around 5' high would be cool :D) I decided on this one just because it would be totally different than the normal cooling setups and looks like I could get by without a peltier for a few months. I'm thinking of putting a radiator on it before it goes back into the bong also (1972 Caprice heater core)
Anyway I was wondering what the best tubing for this would be? Would I be better off using 1/2" tubing or 3/8" tubing? I was thinking that 1/2" would be best because it would allow for a higher flow rate, I'll be using an Eheim 1250 pump, so I figured it would flow better with the higher rated pump. What do you guys think (about the bong and the tubing size?)
Let me know,
Alik

[.. AE 86 ..]

i am using 3/8 and i am more than happy with it

[BrianCapps]

I dont think it matters too terribly much, because you are limited by the bore inside your waterblock and radiator. You would only see a slight preformance increase by going with 1/2 inch tubing. If you DO want to go all-out, use all 1/2 inch with a minimum ammount of adapters.

my $0.02

[o¢r*Aiwa]

Better go 3/8". 90% of the pumps, radiators and stuff are using that tubing size and unless you want to waste your time on getting dozens of adapters for 5% waterflow increase you should be happy with 3/8" (which is ~9mm btw if you read metric product descriptions somewhere).