View Full Version : 3/8 or 1/2

05-28-08, 05:26 AM
so its time for me to change my water setup since ive had it since my 6800 and 3700amd and its 1/4 inch tubing...so heres my question my block on my nb is 3/8 (10mm) and was wondering if i should use 3/8 all around or go with 1/2 (13mm) all around and use a coupling to adapt it from 3/8 to 1/2....will i notice that much of a difference in the heat dissipation or would 3/8 be more then fine i would rather keep it all one size tubing for ease and less amount of fittings.......thanks for the info

05-28-08, 05:48 PM
42 views and no one has any ideas........

05-28-08, 11:44 PM
I'll take a stab. That MB has fixed 3/8" on the NB right? I assume you will be cooling the CPU and GPU in addition to the NB? Are you getting new CPU and GPU blocks and a new pump as well? In general, the 1/2" tubing will provide lower overall head loss, and higher flow through all blocks and thus improved performance. The downside of the mixed 3/8-1/2 system is, as you mentioned, the need to couple and the additional complexity and risk of leak due to the additional connections. You also have to factor in the additional space required due to the larger bend radius required for the thicker tubing. If you do go w/ a mixed system, Koolance has some nice adapters (but be cautioned that they only work w/ the thin-walled tubing so you may need coils to avoid kinks if making any tight turns).

05-29-08, 12:45 AM
My water cooling setup uses 7/16" tubing with 1/2" fittings. It's a bit of a chore to get all the tubes on but it almost guarantees no leaks.

Petra's posted some test results at xtremesystems that basically said there was hardly any improvement in flow going from 7/16" to 1/2" tubing.

edit: oops, that's 7/16" not 3/8"...

05-29-08, 12:53 AM
OK, to better understand what all is going to be in you loop? Radiator, CPU, video card and NB? I think you might be alright with 3/8 as long as you have a good pump, but 1/2 would probably be better...

If you do go with 1/2" I agree with using the coils, they helped my system out quite a bit.

05-29-08, 02:42 AM
its going to be cpu vid nb a black ice pro 2 rad and a koolance hx362 rad with a koolance rk-1000bk res and pump system the pump specs are as listed below
* Maximum Flow Rate: 8.5 L/min (2.25 gal/min)
* Maximum Head Pressure: 4.6m (15ft)
* Motor: Brushless DC, electronically commutated, spherical motor
* Expected Lifetime: 50,000 hrs. MTBF (5.7 years)
* Power Consumption (at max): 18W
* Voltage Range: 8 to 13.2 VDC
* Startup Voltage: 9 to 13.2 VDC
* Maximum System Pressure: 1.5 kgf/cm2 (22 PSI)
* Maximum Temperature: 60C (140F)

05-30-08, 12:25 AM
I guess I'd recommend going w/ 1/2 if it will fit and use the Koolance 3/8-1/2 adapters in/out of the NB. You may want to consider (at the cost of more complexity and connections) using some Y adapters put some of the loop in parallel. I believe that, if using multiple rads, it is best to run them in parallel.

like this (better flow thru CPU at cost of lower flow thru NB&GPU)
pump/res-->[cpu]--+---->1/2-3/8-->[NB]-->3/8-1/2-->[RAD1]--+--> to pump

or this
pump/res--+--[RAD1]--+-->[cpu]-->[GPU]-->1/2-3/8-->[NB]-->3/8-1/2--> to pump

Also, its a crazy idea and I haven't proven it yet but, you can upsize a 3/8" fitting to ~1/2 by first putting a thin-walled section of 3/8" tube over the fitting. I am planning on doing this to adapt my 3/8" pump to 1/2" tubing in my next system to avoid using an adapter. Again, crazy :screwy: so don't blame me if you try it and it leaks.