View Full Version : How much flow rate do I REALLY need?

11-20-2002, 04:38 PM
Found a submersible fountain pump today for $18. It's rated at 120GPH.

Now I know a 150GPH Eheim is pretty popular but it's also pretty expensive. I'm trying to rig my home WC setup for as little $$ as possible.

So my question is how much is minimum for a "simple" water setup? I'm planning on hitting 1800-2000MHz with my AXP1700 T-bred and just cooling the CPU only at this point. My goal is decent cooling and a quiet rig.

I've got the heater core and tube/fittings for a 3/8 inch setup and plan to use a Swiftech block.

Now don't reply with thing like "You really should use a 150-300GPH pump because... um... well that's what everyone uses!". I've certainly read enough posts to know what many folks are using.

Does anyone have experience with multiple rigs running at different flow rates and possibly different tube diameters (i.e. 3/8 and 1/2 inch) to confidently give a minimum flow rate recommendation for my moderate OC goal?

11-21-2002, 05:05 AM
id use a 300 or more personally.... swiftech blocks seem to like high flow rates.... beyond that it keeps has teh ability to keep a more constant flow at a high rate when going up and down the case.... the higher you get the slower the pump goes....

also to save money and get a better pump look into a magdrive pump. swiftech has one and so does this (http://www.aquatictech.com/pumps.html) place.

scroll down to supreme mag-drive pumps.... cheap and fast.

11-22-2002, 02:47 PM
I use a cheap 180gph pump. I've use peltiers with the setup as well.
normal temps are near 40 with my 1600+ overclocked to 1860. With peltier i was getting as low as -12c and typically no higher than 15c uner load. and that was a danger den 2-2.

11-25-2002, 01:55 AM
It all depends on what your block is designed for.

the "open-air" (channeled or mazes) designs need as much flow as they can get,

turbulence generating block can fly with much less flow, and often would outperform above mentions designs in flow-deprived systems.

11-25-2002, 02:31 AM
well..AFAIK..not necessarily more flow = better cooling performance
understand that altho higher flow rate does mean that water moves faster in your block, transfering heat faster

it also mean that the water passing thru your rad is moving fast, thus less time for the fan+rad to cool the water..think about it :)

11-25-2002, 01:58 PM
well what counts for a water-block, also counts for a radiator...

they are both heat exchangers,

fast flow in a block gives better performance, because

1: Delta T is maximized
2: Turbulence is maximized

and those 2 reasons holds true for a radiator too...

the liquid in the system needs to move as fast as possible though the block, and through the radiator. The moment it slows down, Delta-T starts to decrease, and that directly causes thermal transfer to decrease as well.

11-25-2002, 02:08 PM
Well I ended up taking the 120GPH pump back and getting the new Eheim C600 submersible (150GPH). Works great. Um... well it WORKED great until it seems like my 1700 chip just died. :(

At least the water is still flowing...

11-25-2002, 04:31 PM
me loves the best bang for buck danner mag 7 and 1/2" hose system.

With higher flow does that dictate even higher than normal cfm thru a rad or the improved Delta T and turbulence just makes it more efficient.

11-25-2002, 10:02 PM
billa's article over at overclockers.com has very good info on flow rate versus wb design... you should check it out.