Could be radiators if they weren't cleaned prior to installation or buildup over time. Other than that, I agree that the bends actually add up.
I personally witnessed it myself the last few months since I upgraded my DDC's since one of them died of age and had them replaced with two EK D5 G2s in serial. My DDC's needed 40% PWM to flow @ 1.0 GPM. My D5s atm need 90-95%+ to be around 1.0 GPM and I only max out at 1.1 GPM @ 100% when my DDCs went even further than that. Here's the thing though. I went from dual GPUs in SLI to a new single GPU during the new pump installation. You would think my loop should be less restrictive right? What happened you asked? I added another 3-4 90 degree bends. From a total of 14 fittings, I use 4 straights (2 straight barbs for flow meter) and the rest are bends and to be exact, 7 are 90 degrees.
My High Flow meter used to lay flat but now it's facing horizontal upward or vertical instead of it's bottom or back so I'm not sure if that's the cause of the readings I'm getting but the addition bends I had added to the loop and repositioning of the flow meter is when I noticed the flow change knowing the DDCs (35X) have great head pressure compared to the D5s.
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Last edited by GTXJackBauer; 05-17-2019 at 03:53 PM.