Wednesday, April 28, 2010

[Forum Archive '06] Early DDC Top & Pump Performance Comparison

September 2006 saw the debut of my custom, performance enhancing DDC pump tops. Yes, the testing was, by my current standards, quite crude... but it was the best that I could do with the resources I had at the time. Please keep in mind that "DDC+" actually refers to the old orange-impellered 18W DDC-2. Total forum thread views: 60,346 (as of 4/28/2010). As a side note, all images have been re-sized via HTML, rather than my usual two image (preview & full image via link) approach, to speed along the archiving process. You can still right-click on the images and view them at full-size in a new tab/window. Also note that all vBulletin emoticons and their associated code have been removed from the archive entry.

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Okay everyone, I finally got my prototypes back from the machine shop and I also managed to finish the pump testing that I was working on. Feel free to repost this test data where ever you wish as I'll only be posting it in XS and [H]. So, yeah...on with the show!

The Contenders:

I've included the AqX 50Z-DC12, the stock (18W) DDC+, and the Laing D5/MCP655 in the tests for comparison purposes and, as a result, I won't really talk about them in this section.

The Alphacool DDC Top (unmodded) - I didn't bother taking photos of this one because everyone is already pretty familiar with it. In short, it's somewhat large, utilizes 7mm inlets (tested with top inlet) and outlet, is tapped for use with 1/4" BSPP (G1/4) fittings, has a rather sharp outlet curve, and it has additional mounting points integrated into it. This design also retains the 'inlet ring' in the top of the impeller housing.

The Alphacool DDC Top (modded) - Again, no photos... but it's basically the same as the stock Alphacool top. Only differences being that the inlet channel has been enlarged from 7mm to approx. 10-10.5mm (I was going for something more representative of the average modder, as opposed to crazed perfectionist) and, as a result of the enlargement, the inlet ring has been removed.

The Radiical DDC Top - A rather crude design overall, this DDC top consists of a block of acrylic (or Delrin) that has had a shallow cylinder machined into the bottom and, essentially, 1/2" holes drilled to intersect the cylinder, acting as inlet and outlet. The result is a large inlet (with no inlet ring) and an outlet that compromises a large portion of the impeller housing's ceiling. The photos illustrate this best...

Radiical top photos (in acrylic):





The Petra'sTech DDCT-01 (a.k.a. Petra's Top/The Petra Top/whatever) DDC Top - Designed by me and produced by the machine shop that's right next-door (in California, no less! Take that, Swiftech < /joke > )... This DDC top is machined from black Delrin and features a 9.5mm top inlet (with inlet ring), 7mm outlet, a gradual outlet curve, inlet and outlet tapped for use with 1/4" BSPP (G1/4) fittings, and a size/shape/profile which is meant to closely match the footprint of the DDC pump (granted, one end had to be made 4mm longer to allow the threaded portion of the outlet to clear one of the mounting screw holes...it doesn't protrude beyond the top portion of the front integrated mounting bracket). BTW, the 'DDCT-01' naming system will be used to denote revision numbers later in time (e.g. DDCT-01, DDCT-02, DDCT-03, etc.).

Photos:



Internals:




Testing:

Testing & Procedures:

A max head pressure test and several forms of flow testing were performed for each pump at both 12.00V and 13.80V. Each flow test consisted of three timed trials wherein a 5 US gallon Fort-Pak (with 0.5 gallons marked as a start point and 4.5 gallons as the end point) was filled--the results of these trials were averaged and the flowrate calculated. The Fort-Pak was tapped and a barbed fitting inserted to allow for easily repeatable filling conditions and the height of the Fort-Pak's inlet was adjusted so that it was approx. 4.5" above the water level in the reservoir that the pumps were drawing from (to negate any gravitational effects such as siphoning). Power for the pumps was controlled with a rather large, older HP model 6264B variable DC power supply and voltages were monitored using a digital multimeter (below).

Max Head Pressure Testing:

The head pressure tests were carried out using the same setup as I used for my previous round of head pressure tests (shown below).

Test Results:

AqX 50z: 12.00V -- 5.2psig (11.99 feet) | 13.80V -- 6.2psig (14.3 feet)

Laing D5: 12.00V -- 6psig (13.84 feet) | 13.80V -- 6psig (13.84 feet)

Laing DDC+: 12.00V -- 8.5psig (19.61 feet) | 13.80V -- 11.1psig (25.6 feet)

DDC+ w/ stock Alphacool: 12.00V -- 8.1psig (18.68 feet) | 13.80V -- 10.1psig (23.3 feet)

DDC+ w/ modded Alphacool: 12.00V -- 7.8psig (17.99 feet) | 13.80V -- 9.4psig (21.68 feet)

DDC+ w/ Radiical Top: 12.00V -- 5.6psig (12.92 feet) | 13.80V -- 6.8psig (15.68 feet)

DDC+ w/ Petra's Top: 12.00V -- 8.1psig (18.68 feet) | 13.80V -- 10.1psig (23.3 feet)

...and a more graphical representation:

Comments: Now, I'm still not quite sure how the D5 managed to sustain a max head pressure that high...but everything else seems to be about right (and I got that same result with multiple D5's). To be honest, I found the pressure loss due to the Radiical top rather surprising as I didn't think that it would do that poorly.

Max Flowrate Testing:

The max flowrate tests were carried out per the testing procedures described above. A 2.5" section of 1/2" ID tubing was used to link the pump's inlet to the reservoir inlet and a 1' 3.25" section of 1/2" ID tubing was used to join the pump's outlet with the Fort-Pak's inlet (below).

Test Results:

AqX 50z: 12.00V -- 2.83 Gal./min. | 13.80V -- 3.24 Gal./min.

Laing D5: 12.00V -- 3.89 Gal./min. | 13.80V -- 4.28 Gal./min.

Laing DDC+: 12.00V -- 2.25 Gal./min. | 13.80V -- 2.49 Gal./min.

DDC+ w/ stock Alphacool: 12.00V -- 3.19 Gal./min. | 13.80V -- 3.48 Gal./min.

DDC+ w/ modded Alphacool: 12.00V -- 3.61 Gal./min. | 13.80V -- 3.94 Gal./min.

DDC+ w/ Radiical Top: 12.00V -- 3.49 Gal./min. | 13.80V -- 3.82 Gal./min.

DDC+ w/ Petra's Top: 12.00V -- 3.5 Gal./min. | 13.80V -- 3.99 Gal./min.

...and a more graphical representation:

Comments: It's interesting, but somewhat perplexing, that increasing the voltage to the D5 yielded an increase in flowrate but no measurable increase in head pressure.

Experimental Cooling Loop 1 (average restriction):

This was the first of two "real world" flowrate tests--mainly done out of curiosity. This particular test loop consisted of the following:
Reservoir --> 2.5" section of 1/2" ID Tygon --> Pump --> 1' section of 1/2" ID Tygon --> Swiftech MCW60 --> 1' 8.25" section of 7/16" ID Masterkleer --> HW Labs Black Ice Pro Radiator --> 1' 3" section of 7/16" ID Masterkleer --> Swiftech Apogee --> 1' 3.25" section of 1/2" ID Tygon --> Fort-Pak
Photo of setup (with Fort-Pak being drained):

Test Results:

AqX 50z: 12.00V -- 1.71 Gal./min. | 13.80V -- 1.96 Gal./min.

Laing D5: 12.00V -- 2.03 Gal./min. | 13.80V -- 2.12 Gal./min.

Laing DDC+: 12.00V -- 1.8 Gal./min. | 13.80V -- 1.99 Gal./min.

DDC+ w/ stock Alphacool: 12.00V -- 2.2 Gal./min. | 13.80V -- 2.44 Gal./min.

DDC+ w/ modded Alphacool: 12.00V -- 2.34 Gal./min. | 13.80V -- 2.58 Gal./min.

DDC+ w/ Radiical Top: 12.00V -- 1.93 Gal./min. | 13.80V -- 2.13 Gal./min.

DDC+ w/ Petra's Top: 12.00V -- 2.32 Gal./min. | 13.80V -- 2.58 Gal./min.

...and a more graphical representation:

Comments: As the max head pressure data suggested would happen, here you can see the Radiical top losing ground to the Laing D5 (which is kind of sad, considering that the top costs about $48 total to the US...plus the cost of a DDC+). Here you can also see that my top is sitting right about where I thought it would in this sort of loop--between the stock and modded Alphacool tops. Though, really, it ended up performing a lot closer, in terms of flowrate, to the modded Alphacool top than I expected.

Experimental Cooling Loop 2 (high restriction):

This was the second of two "real world" flowrate tests--mainly done out of curiosity. This particular test loop consisted of the following:
Reservoir --> 2.5" section of 1/2" ID Tygon --> Pump --> 1' section of 1/2" ID Tygon --> AqX MP-1 GPU --> 1' 8.25" section of 7/16" ID Masterkleer --> HW Labs Black Ice Pro Radiator --> 1' 3" section of 7/16" ID Masterkleer --> AqX MP-05 SP LE --> 1' 3.25" section of 1/2" ID Tygon --> Fort-Pak
I don't have a photo for this one... but it was set up in the same way that the previous test loop was.

Test Results:

AqX 50z: 12.00V -- 1.08 Gal./min. | 13.80V -- 1.22 Gal./min.

Laing D5: 12.00V -- 1.18 Gal./min. | 13.80V -- No Data.

Laing DDC+: 12.00V -- 1.29 Gal./min. | 13.80V -- 1.48 Gal./min.

DDC+ w/ stock Alphacool: 12.00V -- 1.36 Gal./min. | 13.80V -- 1.57 Gal./min.

DDC+ w/ modded Alphacool: 12.00V -- 1.38 Gal./min. | 13.80V -- 1.59 Gal./min.

DDC+ w/ Radiical Top: 12.00V -- 1.12 Gal./min. | 13.80V -- 1.29 Gal./min.

DDC+ w/ Petra's Top: 12.00V -- 1.36 Gal./min. | 13.80V -- 1.55 Gal./min.

...and a more graphical representation:

Comments: Now, this test I don't really consider that accurate, as far as my own top is concerned, because it was the first test done with the prototype and it was carried out late in the evening, several days after all of the other testing (i.e. human error). Though, really, the results between both Alphacool tops and my own are so close that the differences could easily fall under 'margin of error.' At higher restriction, I would expect my top to perform a tiny bit better than the stock Alphacool top and the modded Alphacool top due to it matching the max head of the stock Alphacool top and exceeding the max flow. Granted, the differences I'm talking about here are so small that they would likely never be noticed in an actual cooling loop.

Anyway, you can see the Radiical top is, yet again, bested by the D5... However, this time the stock DDC+ has also joined the D5 in out-flowing the Radiical top. Speaking of the D5, you're likely wondering why there's no 13.80V data for that test. Well, as we were finishing up the D5's 12V testing, it had the misfortune of ingesting a small rock which, even after removal and cleaning, resulted in the pump being no longer able to produce consistent results and occasionally failing.

Random Photos & Comments:

Take what you will from all of that... but I think that things went pretty well. Also, thanks to Margaret for helping out with refining/helping with the tests and providing that spiffy power supply. I'll work on getting pricing and such figured out for our DDC tops this week as I need to speak with the guys at the machine shop to see what can be done. Also, I likely won't be able to address any questions until Monday afternoon since I'll be spending most of Monday morning driving back from SLO.

Whee! Random photos!

Margaret prepping between trials...while I play with the camera

Our newly re-built water cooled Cardboard Box Computer (this time around, I went for the USPS Edition Tech Station look):


Extended Testing Results:

Series Testing:

Anyway, as I mentioned, I don't have enough of the other tops to do dual pump testing (only have one stock Alphacool, one modded Alphacool, and one Radiical) so I ran the tests with my two prototypes and compared them to the results I obtained previously for my top. There was no point in attempting to do max head pressure testing with the dual pump setup as it would likely exceed the max pressure my gauges can measure (15psig). As such, I stuck to loop testing only. The only change made to the loops for these tests was the addition of 1 foot of tubing to link the pumps.

The Twins:

Now, I realize that I didn't join the pumps in the most ideal way... I just didn't think of it until I was finished. Anyway, it shouldn't make a detectable difference, as far as this method of testing goes.

Experimental Cooling Loop 1 (average restriction):

Test Results:

DDC+ w/ Petra's Top: 12.00V -- 2.32 Gal./min. | 13.80V -- 2.58 Gal./min.

2x DDC+ w/ Petra's Top: 12.00V -- 2.78 Gal./min. | 13.80V -- 3.08 Gal./min.

...and a more graphical representation:

Experimental Cooling Loop 2 (high restriction):

Test Results:

DDC+ w/ Petra's Top: 12.00V -- 1.36 Gal./min. | 13.80V -- 1.55 Gal./min.

2x DDC+ w/ Petra's Top: 12.00V -- 1.84 Gal./min. | 13.80V -- 2.05 Gal./min.

...and a more graphical representation:


Parallel Testing:

Experimental Cooling Loop 1 (average restriction):

Test Results:

DDC+ w/ Petra's Top: 12.00V -- 2.32 Gal./min. | 13.80V -- 2.58 Gal./min.

2x DDC+ w/ Petra's Top (Series): 12.00V -- 2.78 Gal./min. | 13.80V -- 3.08 Gal./min.

2x DDC+ w/ Petra's Top (Parallel): 12.00V -- 2.43 Gal./min. | 13.80V -- 2.78 Gal./min.

...and a more graphical representation:

...more evidence that, even in a somewhat low restriction loop, parallel pumps don't do much.

Additionally, I fiddled around and determined that the DDC+'s will start at up to about 13.19V--to achieve anything above that, you have to start the pumps at that point (or below) and then increase the voltage to the desired amount (13.8V, in this case).

Oh, yeah, take a look at this.... (the sample barbs that Eddy was nice enough to send to me arrived yesterday)

...I'm such a tease

*edit...again*Here are some updated photos:

The machine shop decided to put a MUCH nicer finish (internally and externally) on the production version than they did on the prototypes. The tops are so smooth that they're shiny and a little reflective!!! (though, tooling marks can still be seen... the photos really don't do the finish justice)







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