Quote Originally Posted by Johnny87au View Post
If you look at martin's pics one pump does feed into the other, which is series.. Similar to the dual bay xspc reservoir i've owned and never had any real issues..
Yes, but that looks like an inlet to the res that feeds the pump, rather than the pump inlet itself - if you look at testing for restops for a single DDC, you'll see that the XSPC res top always comes out on top because of that little tube which dumps water straight into the inlet of the pump. I would assume the same logic would apply to dual pumps - pumping into inlet is better for flow/pressure than pumping into res chamber that feeds inlet.

Quote Originally Posted by Martinm210 View Post
Will need some testing, but I don't think the res filled amount matters as long as it's adequate to prevent air from pulling out the outlet. I suppose there might be some frictional energy loss dumping into a reservoir, but the pressure energy remains regardless.

I also think you'll get roughly the same thing with separate pumping loops but shared reservoir. I personally would probably keep two loops and just share the reservoir to maximize CPU flow rates. The only real benefit to series is to have redundant pumping. With an rpm sensor, it's pretty simple to connect that to the cpu fan header and set a shutdown rpm.

Anyhow, I don't know much about these...just speculating.
Will certainly need testing, I agree. I see this as essentially being the same as running 2 pumps in series but having pump 1 dump water into a reservoir that feeds pump 2 - which is something nobody has really tested before because there hasn't been any reason to. As for benefits of series, don't the older EK Supreme's benefit a lot from the extra pressure?

Anyways Tim from Koolance, sorry for the derailing the thread slightly. I'm just very interested in these small details that are, from a max-OC/temp standpoint, largely inconsequential.