Which pump should I choose

DCP 2.2 and CPX-1 are the same pump - Jingway 600's

The DCP 4.0 is the Jingway 1200

As you say the 4.0 is better, however if you are doing a CPU only loop with low restriction components then there is no real advantage to having the 4.0.

Also the Jingway 600's run pretty much silent when properly decoupled from the case. I have one and I can't even hear it over the PSU fan when bleeding / leak testing the loop.

The 2.2 and the CPX-1 is not the same, its made by the same OEM but the 2.2 has a lower flow but higher static pressure then the CPX-1, the 2.2 is also a bit smaller then the CPX-1

I have heard differing reports on the 4.0. Some people have said that it is very loud, some that it is about the same as a D5 (fairly quiet) so it seems to be quite variable.

There may have been a bad batch out there, or maybe people's perception of "loud" and "quiet" vary a lot.

I would say if you are running AP-15s at full then you are unlikely to hear the pump over them. Make sure you decouple it well though, I used some PT Gel Stuff which did the trick, but a foam pad will work just as well.

Here is Martin's test on the CPX-Pro (DCP 4.0), it includes a video so you can judge the sound yourself.

You are right, EK are selling the DP-400 as their DCP2.2 and Danger Den are selling the DP-600(ish - doesn't exactly tie in with Jingway's specs).

I wonder when that changed, I have a DCP 2.2 and it is definatly a Jingway 600 (from the size)

That is the Jingway DP-600P. Performance wise sits in between the 400 / 600 and the 1200. Not sure about noise and quality though, not seen many reports on them.

Here is Skinnee's comparison of the three Jingway pumps.

Same OEM.

Preceived silence is always diffecult to measure based on another's comments. Actual data like Martin's testing sure is handy to determine the outcome. With that said, also look over at Martin's site for the acustic methods to quiet some of those pumps down for mounting. Things to watch out for are:

- Bay RES pump combos. Pump vibration with no isolation can rattle even the quetest pumps in a HDD cage setup.

- RES top on pumps. The RES with a hole in the bottom feeding the pump without a flow deflector introduce a swirling vortex of flow. The RES top would make your pump into a kitchen blender in no time flat. A really quiet pump is useless then. Martin has a good write up about using a flow deflector for the RES top on pumps.

- Having the pump with a restrictive inlet flow can cause cavitation. This in turn can cause unwanted noises, bubbles, loss of flow performance and premature pump failure. It's always wise to have a RES prior to the pump and no more than 4-inches way from the pump.

- Never run the pump upside-down (impeller) to gravity. It's like night and day from quiet and noise in a WCing loop.

- In some instaces, having your pump mounted to a flat part of the computer case with a fan running can cause a harmonic noise problem that is very annoying. Between the two, the rpm's are fighting each other on the flat substraight allowing noise reverb to happen.

There are other causes of making a quiet pump noisey as well, but these tend to be the most common.

Hope this helps ...
Edited by bmaverick - 5/9/12 at 10:57am

I'm one of those people who class the EK DCP 4.0 (and the Phobya variant) as noisy at full speed. I've run them fully decoupled apart from the tubing and even used softer tubing to to try to reduce the transmitted noise. I find them annoyingly 'buzzy' and could certainly hear them over 4 of the old style AP-15s.

At 5v though they're both very quiet albeit with significantly reduced flow rates although still suitable for a simple loop. The specs say that 8v is the minimum start up voltage but I used one of them for over a year at 5v without problems.