Originally Posted by bmaverick
It seems that this review is a little biased towards the newer pump. The newer pump has G1/4 barb fittings, so out of the box the flow rating will be greater when the same power is applied.
This review would have been best to match the DDC pump with the CPX-1 and the CPX-Pro against the D5.
Or even better matching the CPX-Pro with a DDC 1/2" inlet side pump.
So, the CPX-Pro uses a scroll volute now like the Laing pumps. Copying is a sign of flattery.
The scroll shaped volute is only 2D due to machining vs. the 3D type the Laing uses. Also, the paddle wheel blades do not take advantage of the scroll volute since the blades are not forward/backward curved. So, there is actually a pumping lose during the flow expansion. This equals in a lose in overall efficiency. The early C-Mag pumps had this problem too.
Just like the C-Mag pumps, this pump has the chance of leaking fluid into the pumps electronics. The Laing pump impellers turn on the ceramic ball and spin via a magnetic field. These new pumps have a ceramic sleeve that travels down to mate with the motor. Will this pump hold out like the Laing pump for 50,000+ hours of warranty operation?
"...so the DDC at that point is consuming about 40% more power which in the end becomes added heat to the loop."
Having the maglev impeller on the Laing pump, less heat is actually dumped into the cooling liquid. You will need to place an inline thermal coupler to properly measure this.
Sure the only Con is it's size. However, one must look deeper into the other 5-why questions for quality and construction.
Even though this newer pump holds some promise, I would use great caution before saving a few extra dollars in buying one over a proven DDC at this time.
I wish I had another $55 pump to compare against, but the stock DDC was the closest pump I could think of. Not sure how that's biased, I always try to be as scientific and emperical as I can be. What comments or data did you specifically find biased??
I don't have a CPX-1, but it's about 1/3 of the pumping power, so I'm not sure that helps. I have curves for those, but I've seen too much error in comparisons with any test results that are not done on the same test bed, so my preference is to compare with other results I have developed myself. I do have a D5 though, and when I retest it measuring total dynamic head I can provide an apples to apples comparison. I personally don't care much about comparisons, I'm more interested in just gathering the performance data to plug into the estimator. I focus on providing data not comparisons...it's just something I throw a little bit in there because that's what people want.
Also the volute is a spiral shape, and it's not from Laing's designs, spiral shaped volutes are common to alot of centrifugal pumps. Actually the Laing DDC 3.2 stock top is not a spiral shape, it's semispiral approximated with two circular curves, so it's not copying anything from Laing's pumps, completely different design all together.
Couldn't tell you on the MTBF, that's a question you just can't answer in a review. I can tell you it uses a ceramic shaft just like the Iwaki RD-30 which is built like a tank and last many times longer than any of the Laing pumps, so the construction methods are sound.
I agree on the straight impeller blades, I would have liked to see curved blades or an encased impeller like the DDC, but sometimes simple is good and the less wetted perimeter and friction the higher efficiency (There's always tradeoffs). It also always trickles down to the end cost, you just can't expect $200 Iwaki construction. Also the pump may not be designed specifically for water cooling and clean fluids. A more open impeller like this is preferable when you start talking about solids in fluids and the pumps ability to move something not perfectly clean. I don't think any of the pumps we used today were designed only for watercooling, there are other purposes in mind like ponds, aquariums and other fluids that often are not as controlled and clean like computer loops. We also owe our radiator performances to the automotive industry, alot of things are hand me downs from other industries.
In the end, I was just happy to see another option. Prior to this the common pumps were either quite a bit smaller and less powerfull than a D5 or DDC, or they were alot stronger like the Iwakis. Most of the pond hand me down pumps were heavily weighted in the high flow low pressure side. This pump seems to have promise in providing similar high pressure performance to a stock DDC 3.2, better performance than a DDC 3.1, and slightly lower performance than a D5 or DDC 3.2 with top. But it does that while being quiet, efficient, and at a very attractive price. Only time will tell on the durability piece.
I like alot of pumps, I have two D5s, a D5 basic, a DDC 3.2, a DDC 2, and XSPC dual bay res pump, and now this CPX-pro and they are all good pumps.