[Watercooling] Two different pumps slightly different GPH big deal?

[Theguynextdoor]

Hey guys I have a Swiftech MCP655 and Alphacool VPP655 pump in my system. Same reservoir on both just wonder how big of a deal it is if they're in the same loop but running at slightly different flow rates. The Swiftech puts out 317GPH while the Alphacool puts out 396.

The flow order is this pump 1>CPU>radiator>pump 2> GPU's>radiator.

I want to keep them in the same loop for redundancy in case one fails. I could just make them separate loops if there is reason for warrant.

Any tips?

Here are the pumps and their flowrates:

http://www.frozencpu.com/images/awards/pumpchartpdf.pdf

http://www.frozencpu.com/products/1...ad_Ports_Perfectly_Tapped.html?tl=g30c107s153

http://www.frozencpu.com/products/13147/ex-pmp-131/

Tried googling but not finding much info.

 

[Billb2]

No, those are not the pumps flow rates. They are the maximum flow when the pump is not working against any pressure, and the pressure when the pump is not moving any water, neither of which happen in the real world.
You need to find the P-Q curves for the pumps. That will tell you how they perform in "real" situations.

And to answer your question, it's no big deal.

 

[aigomorla]

they are the same pumps.

the 655 most typically denotes the laing D5 pump.

You dont need to worry about anything as they are the same pump.

 

[Theguynextdoor]

Awesome thanks for the thorough and concise replies guys. Aigo I heard that before, but home come the alpha cool has like a switch on it with 5 settings while the swiftech has a PMW cable? I trust your advice and am assuming that that is just different ways the companies package/setup their pumps for sale.

 

[Theguynextdoor]

Ok after filling up the system with water using only the swiftech pump I finally turned on the alphacool thing is like a turbocharged V8 compared to the swiftech which sounds like a 90's V6 Cadillac.. Any clues to why?

EDIT: After filling both reservoirs to full no big deal anymore.

 

[guskline]

Let them run for at least 24 hrs to purge the air bubbles from the system, then listen to them. Be sure to keep your reservoir filled.

 

[Aikouka]

As they mentioned, they're just Laing D5 pumps with different control mechanisms. So, if I had to guess, the advertised flow rates are higher for the one because its maximum RPM is higher.

 

[aigomorla]

Ok after filling up the system with water using only the swiftech pump I finally turned on the alphacool thing is like a turbocharged V8 compared to the swiftech which sounds like a 90's V6 Cadillac.. Any clues to why?

EDIT: After filling both reservoirs to full no big deal anymore.

it can be a factor of several things.

The impeller chamber in the other can have air inside it which is causing that noise while its bleeding.

Its basically chopping up the air bubbles into tiny tiny bubbles, which is making that turbo noise your talking about.
It should go away after all the micro bubbles have bleed out.

Another thing is the speed setting on the D5's.

The Swiftech D5, if its not a Vario model, meaning doesnt have a speed dial on the rear, is cap'd at setting 4, while the Vario model can go up to 5.
(this is why the vario version is typically a bit more expensive)

However this wont hurt either of the pumps as the D5 was designed to run at X RPMS, and having one at 5 while the other at 4 will not damage the impeller chamber as they were both designed to run at X RPMs, only ur limited at 4 on the non vario.

So again... nothing to worry about, and enjoy your LC system.

 

[Theguynextdoor]

Let them run for at least 24 hrs to purge the air bubbles from the system, then listen to them. Be sure to keep your reservoir filled.

Thanks, it was just how I had the reservoir sitting so that one would never actually fill to the top since the water level it only go as high as the in/out ports. The res/pumps are higher then the radiators so it wasn't hard/long before all the air bubbles left.

As they mentioned, they're just Laing D5 pumps with different control mechanisms. So, if I had to guess, the advertised flow rates are higher for the one because its maximum RPM is higher.

Makes perfect sense especially in conjunction with what aigomorla posted.

it can be a factor of several things.

The impeller chamber in the other can have air inside it which is causing that noise while its bleeding.

Its basically chopping up the air bubbles into tiny tiny bubbles, which is making that turbo noise your talking about.
It should go away after all the micro bubbles have bleed out.

Another thing is the speed setting on the D5's.

The Swiftech D5, if its not a Vario model, meaning doesnt have a speed dial on the rear, is cap'd at setting 4, while the Vario model can go up to 5.
(this is why the vario version is typically a bit more expensive)

However this wont hurt either of the pumps as the D5 was designed to run at X RPMS, and having one at 5 while the other at 4 will not damage the impeller chamber as they were both designed to run at X RPMs, only ur limited at 4 on the non vario.

So again... nothing to worry about, and enjoy your LC system.

Thanks good to know.

This is only my third LC setup and really happy with it since time and budget I finally got everything I wanted together. (I wanted a desk case setup) and really happy with it. The Swiftech I got though is supposed to be PMW controlled but I don't really want to deal with that cause neither one is even loud at full speed.