HAHAHA, some people dont know what they are talking about!

Some friends tried to convince me that by using 1/2inch tubing a MAXIMUM GPH was 70 with ANY PUMP... HAHAHAH, i use 1/2inch on a ehime 1250 and get what 280 or so GPH, no head, 10ft flat layed out tubing with no restrictions~ ( a test)

Then they fried a 4th MB between the 2 of em~
Also tried to convince me a Black Ice pro is better then my heatercore.... MUHAHAHAHAH!!!!

God.... no offence but these two are major N00bs....

why would anyone think that size of the pipes give you a max flow rate. you should teach them the basics of electricity. Watts, volts, ext. then you can relate that to water flow.

lol, thats kinda funny, 3/8 tubing can have a maximum of like 300gph, thats under a ton of pressure I supose too.

btw, your gpu top should be on its way to me

Sounds like their knowledge of water cooling is about equal to MaximumPC's

I think they meant: "max effective flow rate", or max efficient: you shouldn't go higher than 3 gpm (180 gph) with 1/2 tubing, because your flow speed reaches 5 fps, and that'll create a huge pressure drop. Actually, you want to keep it at 2 to 3 fps (feet per second).

At 70 gph, the pressure drop would be almost non-existant (i.e. insignificant) within the tubing. That's good, if your block/rad can drop the rest of the pressure, because that's where you want the pump's effort to be, not within the tubing.

Hold on to your friends: they'll straighten up, sometime...