Koolance RP-452×2 (Rev2.0) Dual D5 Pump Dual Bay Reservoir Combo

Dual pump performance is far better when the pumps are in series and so the unit was reconfigured to test this.  The reservoir was joined but only connected to the first pump.  Performance with both pumps at 24V is of course extremely high:
The Alphacool performs poorly because it is the only setup that is *not* in series.  Instead the pumps are connected in parallel with a “T” connector.  The Alphacool by design does not allow a “true series” setup and so we are unable to test it in the optimal setup.  Of course so much pump pressure is only needed for more restrictive loops or loops where extremely high flow is required:
The main benefit to using dual pumps of course is maintaining good flow rates while being able to turn them down to near silence.  With both pumps at 12V, performance is similar to one pump at 24V but with much less noise:
If we look at the actual expected flow then we see very respectable numbers for most loops:
It is to be noted that the RP452x2 Rev 2 is also compared to the Rev 1.3.  The Rev 1.3 orientates the pumps differently and allows for a simpler and more free flowing setup.  However it is far harder to work with in terms of filling and bleeding the loop.  The small performance difference in our opinion is very worthwhile.