pumps in series?

[boorishid]

When you run pumps in series do they have to be the same rating? It seems to me if you put a more powerfull pump in front of a smaller pump the stronger pump isnt going to get enough flow, and if you put the smaller pump in front of the bigger pump its going to bottle neck the flow?

[muddocktor]

Yeah, generally you want to go with the same model pumps if you are going to do a series setup, for just the points you mentioned. The pumps would have to have at least very close flow rates and pressures to do this if you would use dissimilar pumps.

[Conumdrum]

Agreed on the must be the same pumps. Using two pumps isn't needed for a basic res, pump, rad NB/GPU/CPU as long as the parts are free flowing. My loop is fine as is with one pump. Having two would be nice tho! Redundacy, no worry about too low flow rates etc.

It's a fuzzy area, like fractal math. It all depends.......

[axis01]

EK makes this dual DDC top (http://www.performance-pcs.com/catalog/index.php?main_page=product_info&cPath=439&products_id=24124) where you can run dual DDC 3.X pumps. I've never run dual pumps but from what I understand, it's only good for redundancy. You gain little to nothing as far as gpm and head pressure are concerned..

Axis

[thorilan]

you gain quite a bit of flow rate on more restrictive systems with dual pumps.
you dont double the flow but the series pumps overcome the restrictive resistance of the loop allowing the flow to reach much higher on the curve

[Moto7451]

These days unless you're running a lot of blocks (i.e. a somewhat restrictive CPU block and three full cover waterblocks, NB block, etc) it's not really necessary.