Interesting information. Thanks for posting.
But it is not a cooler to cooler comparison .. it is instead a comparison of how different coolers perform in a given system.
I started seeing red lights and and hearing alarm bells as soon as I saw OC3D results showing CLCs having 5c cooler temps than D15S at stock settings in your posted graphs. Quick look at review criteria shows their test system is in a Air 240 case in 'a temperature controlled room'. I'll assume this mean they are using room ambient temperature (20c) and not the air temp going into cooler during testing
Their testing at the very best is only showing us how well their system (in Air 240 case) performs with different coolers.
I don't have a system identical to theirs so their test results means nothing to me. I'm more interested in how coolers perform against each other .. as in each receiving the same temperature air going into cooler .. or at the very least using the air temp going into cooler as baseline for delta temps insread of the air temperature of room test system is in .. which obviously is not the same as cooler intake air temp. IMHO scratch that .. It is a fact that testing of coolers inside a system using air temperature of 'a temperature controlled room' for baseline air temperature gives us no idea how coolers are actually performing against each other.
To know how the cooler perform we have to have testing based on cooler intake air temp. We need this to rule out the effects of case and system have on the airflow temp going into cooler. Therefore we have no idea how well each cooler performed, only how each cooler performed in their specific test system .. so unless you have an identical system OC3d test results are virtually worthless.
Using a case with 2x 140mm intake and 1x 140mm exhaust fans for air coolers versus 2x 140mm intake and 1x 140mm exhaust fans then adding the CLC fans to other vents as intake/exhaust changes case airflow dramatically.
Each air coolers' fan and airflow can also dramatically change the case airflow .. and any change in case airflow almost always changes the cooler intake air temperature
If we change the cooler intake airflow 3c, the CPU temp will be 3c warmer .. 6c warmer air into cooler results in 6c warmer CPU temp. While this is difference is not always exactly a 1:1 ratio, it is very close.
Custom loops air temp changes are not 1:1 .. it can be 5c change in air temp to 1c change in CPU temp .. all depends on components and water temp. I do not know how much closer to the 1:1 ratio CLCs are .. not even enough to guess.
But the changes in case airflow in air 240 with different air coolers is going to be noticeable .. I have seen 4-7c differences in cooler intake air temp depending on case airflow setup and what air cooler is being used. I'm sure their case testing of CLCs versus air cooler is at least as much more.
Last I knew the EK Predator is no longer being sold.
Mid-range coolers like H5, TRUE Spirit Direct, H7 (wish the new H7 Quad w/ 4x 6mm heatpipes was out), Macho Direct, etc do a very good job and are only a few degrees below top tier coolers lke Dark Rock Pro3, NH-D15S, R1, Silver Arrow IB-E, PH-TC14PE, TRUE Spirit 140 Power, NH-U14S, Archon IB-E X2, etc.
I would like to see testing of all the above based on airflow temp into cooler ..
adding Alphacool, be quiet! Silent Loop, Swiftech X2, etc all with same size radiator too. I don't care about CLCs and their test results. Maybe I'm too picky, but I want an AIO with a fill port, proper fittings, copper radiator .. a system I can maintain with components I can replace if needed.