DDC Top & Pump Performance Comparison (Petra's, Radiical, Alphacool, etc.)

Petra

Gawd
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Jul 8, 2003
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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! :rolleyes:

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):
radiicalTop1.jpg
radiicalTop2.jpg

radiicalSide.jpg

radiicalBottom.jpg
radiicalBottom2.jpg


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 :p </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:
top_mount_side.jpg

top_mount_top.jpg

top_mount_close.jpg

Internals:
DDCT-01-1.jpg

DDCT-01-5.jpg

DDCT-01-6.jpg



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).
BIG_PSU.jpg


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).
TESTCSP_MAG.jpg


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:
maxPressure.jpg


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).
FlowTest.jpg


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:
maxFlow.JPG


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):
ApogeeFlowLoop.jpg


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:
flowLoop1.jpg


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:
flowLoop2.jpg


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. :(
 
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Petra

Gawd
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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! :D

Margaret prepping between trials...while I play with the camera :rolleyes:
MargaretTesting.jpg


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

USPS_CBB_detail.jpg



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:
tehTwins.jpg


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:
dualLoop1.jpg


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:
dualLoop2.jpg



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:
parallelChart.jpg


...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 :D )
topEddyBarbs.jpg

...I'm such a tease :p
 
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danks

Limp Gawd
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Jul 3, 2005
Messages
241
I was waiting for this Petra, excellent work! Can't wait to get one!

P.S. Will you be offering the ddc ultra with top already fitted as a kit?
 

madmat

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shoman24v said:
All that extreme testing and you forgot to use hose clamps :(

If you're using 7/16" tubing on 1/2" barbs hose clamps are purely optional. Trust me on this.
 

aldy402

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nice results and thanks for the time you put in

have you already started on mass production? pricing?
 

Erasmus354

[H]F Junkie
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hmmmmmmmmmmmm.....hmmmmmmmmmmmmm

very nice testing indeed, looking forward to rev 2 :)
 

thunderstruck!

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danks said:
I was waiting for this Petra, excellent work! Can't wait to get one!

P.S. Will you be offering the ddc ultra with top already fitted as a kit?
What's the point of selling it together? Do people really buy a DDC to run it at stock? :)
 

danks

Limp Gawd
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thunderstruck! said:
What's the point of selling it together? Do people really buy a DDC to run it at stock? :)

Ohh no I meant the ddc with Petra's top already fitted... wouldnt want to run it stock :)
 

thunderstruck!

[H]ard|Gawd
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I was being sarcastic. Just pointing out that petra would make more money selling it individually than offering a discount, since most people will buy his top anyway with a purchase of the pump
 

danks

Limp Gawd
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Messages
241
thunderstruck! said:
I was being sarcastic. Just pointing out that petra would make more money selling it individually than offering a discount, since most people will buy his top anyway with a purchase of the pump

True, didnt think of that... I'll take my seat now :)
 

Adidas4275

Supreme [H]ardness
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this is great. I was just saying in another thread that there should be a comparsision between dcc tops and what makes them better...

thank you so much for this great info.....

if my alphacool top ever breaks ill buy a petra's top.....
 

Erasmus354

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thunderstruck! said:
I was being sarcastic. Just pointing out that petra would make more money selling it individually than offering a discount, since most people will buy his top anyway with a purchase of the pump

For a lot of people a big advantage of the DDC pump is its small footprint. It makes it an extremely attractive pump for SFF watercooling, or for sticking in a spare drive bay to provide for possible cleaner mounting. As the tests have shown the different tops dont provide incredible performance increases, about 35% increase. While that is a great increase if you want performance, if you want size it isn't too much to worry about.

So there are quite a few people who would purchase the pump to run it stock...because the pump run at stock is still pretty damned good. And for many the change in form factor (provides significant changes to tube routing going from parallel to perpendicular input/output) and the increased cost is not worth it for the performance increase.
 

Adidas4275

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the alphacool modded top atleast has mounting brackets w rubber on them to remove vibrations when mounted in a 5.25 drive
 

BillParrish

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I am curious about the 3d models of the new top. In particular I noticed how the "tunnel" from the pump chamber to the outlet fitting is of one continous diameter and does not line up (centered) with the outlet. I see there is an elevation change there but was wondering if you considered expanding the outlet end of that passage to make a smooth transition with the outlet fitting, I.E the end of the passage gradually increase in cross sectional area and at the end have the same diameter as the ID of the fitting to be installed and centered on that fitting.

Perhaps its a limitation of the software used.

great post !!! the "real world" flow tests were of great interest.
 

MassiveOverkill

[H]ard|Gawd
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If you could add a second return port perpendicular to the current one (basically the stock fill port location) I would buy it in a hearbeat. On the alpha top, I use that second return port as my T-line:

4thH20rig005.jpg
 
D

Deleted member 134350

Guest
GREAT JOB Alex! :cool:

I would like to see mounting holes and rubber isolation mounts offered. AlphaCool was very smart to include the mounting kit so the pump could run silent.

P.S. This is kinda picky but I would lose the brackets ( [] ) around the model number of the pump. DDCT-01 would be cool as it is. JMO
 

Petra

Gawd
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Several hours and a 192 mile drive later.... :rolleyes:

Okay, let's see... where to start...

We haven't started our first production run yet (wanted to wait until after I had a chance to test the prototype and correct design problems, if any) and, as such, I don't have any definite pricing yet. However, that said, we're aiming for a retail price between $25 and $28 for the top with barbs included (there'll be an option for either DD G1/4 High-Flow barbs (NOT the 'Perfect Seal' barbs) or EK G1/4 barbs). Personally, $29 for the Alphacool top without barbs is a little much. Then again, there's the Radiical top.... let's just not go there. ;)

We'll likely be selling the tops individually, as well as in a pump + top combo at a small discount.

BillParrish: It's not a limitation of the software, you can do pretty much anything with Solidworks. You have to keep in mind that this is a machined part and, as such, the more intricate and complex it is, the more it costs (per unit) to make. Additionally, there may be some tooling issues with that sort of outlet, depending on how gradual the diameter increase was. If one were to manufacturer these via multi-part injection-molding, then those sorts of design details wouldn't really pose a problem. My goal was to design something that performed well and wouldn't be overly expensive to machine.

MassiveOverkill: I'm considering doing something like that for the eventual Rev.2.... but, for now, I'm just keeping things simple.

SiGfever: Yeah, I'm considering losing the brackets around the model number (Quoc also suggested this). As for the screw mounts and such, I may end up doing that with a future revision... though, I'm really not a fan of hard-mounting pumps.

Also, as a side note, the DDC+ doesn't seem to start at much over 12V... You have to start the pump at around 12V and then increase the voltage to 13.8V.
 
D

Deleted member 134350

Guest
@Petra,

I was scepticle about hard mounting my DDC-2 after having my D5 on your Gell Stuff. I have been VERY happy with how quiet it really is. The rubber bushings isolate the pump and it is very hard to hear it at all. Even when I was leak checking it with a 250w power supply the power supply fan masked any sound of the pump and the power supply is very quiet.

Being able to mount it opens up so many possibilities and using the Mountain Mods hard drive brackets to mount it to a 120mm fan is appealing if for no other reason than the pump motor cooling aspect alone.

P.S. I linked this thread in "ocforums.com".
 

FroggyTaco

n00b
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Petra said:
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.

As in San Luis Obisbo?
 

FroggyTaco

n00b
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Petra said:
Yes, that would be where I was... I go down there quite often, actually.

Well then you drive by my house in San Miguel! Be sure to wave next time as you drive by! :cool:
 

el rolio

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Erasmus354 said:
So there are quite a few people who would purchase the pump to run it stock...because the pump run at stock is still pretty damned good. And for many the change in form factor (provides significant changes to tube routing going from parallel to perpendicular input/output) and the increased cost is not worth it for the performance increase.

dont forget however E, that stock means 3/8" plastic barbs on the end. with the modded tops were were all able to choose exactly which barbs we wanted. me personally i got some EK 1/2" g1/4 barbs on mine.
 

el rolio

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Petra said:
Several
SiGfever: Yeah, I'm considering losing the brackets around the model number (Quoc also suggested this). As for the screw mounts and such, I may end up doing that with a future revision... though, I'm really not a fan of hard-mounting pumps.

Also, as a side note, the DDC+ doesn't seem to start at much over 12V... You have to start the pump at around 12V and then increase the voltage to 13.8V.

hey! i like the brackets! but i wouldnt die if you took em out. it just looks nice what with the machined name in the particular angular font and all. i hope i really am not the ONLY one liking it and im sure an thinly etched name wouldnt stop anyone from buyin it now would it?

second, as the XS thread was down, i asked over there, HOW DO i get my volts up for the increased rate? is there only one way and that with test equip like you used or any other ways? in my regular computer setup?
 

Bbq

King of Charts
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Suggestion: For additional x dollars, you may have a custom engraving in there in place of petrastechshop.com...

I know what I'd get. [H].
 

Petra

Gawd
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el rolio said:
second, as the XS thread was down, i asked over there, HOW DO i get my volts up for the increased rate? is there only one way and that with test equip like you used or any other ways? in my regular computer setup?
I can think of three ways in which you could run a pump (or whatever) at 13.8VDC in your computer:

1) Having a second PSU that's a dedicated, single output 13.8V PSU
2) Using a separate variable PSU (as I did for testing)
3) Building/modding/buying a 12V to 13.8V DC/DC step-up voltage converter and plugging it into your computer PSU's 12V rail. Hypothetically, you may be able to modify a laptop car power adapter for this purpose, depending on its specs.

Now, none of these options, aside from the variable PSU, solve the issue of the DDC not starting at much over 12V. Margaret and I have been tossing around the idea of designing a 12V to 13.8V DC/DC converter for this exact purpose (as a little project)... but, there are some challenges. First, it would need to be able to handle a current draw of up to 3 or 5A (to accommodate dual pump setups with various DC pumps). It would need to have some sort of timed relay or some-such that would allow the unit to bypass the DC/DC converter for a certain amount of time (a little more than enough for a couple DDC's to complete their startup cycle) and then switch over to outputting 13.8V. Lastly, an ideal unit would be able to accept a 12V input (+ or - 5%) and still output roughly 13.8V.

Anyway, just something we've been thinking of... I'm not sure if we'll have time to go through with it, but it would certainly be interesting.
 

el rolio

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well, that answers my questions perfectly, i kno crediki had told me before i cant, but i wanted to make sure. all the info now has made it clear in my head so i understand. so to recap:

you produce the tops -- ima buy one
you produce the DC stepper up -- ima buy one
you sell the gel stuff -- i need to get one this week! **EDIT** ORDERED! :D

and yea as you kno from over at XS. we HIGHLY recommend the EK barbs with all the stuff you will be selling. like make them the default choice or supn, instead of the perfect seals, when the web page needs to be made. (plug plug plug)
 

penguin

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SiGfever said:
GREAT JOB Alex! :cool:

I would like to see mounting holes and rubber isolation mounts offered. AlphaCool was very smart to include the mounting kit so the pump could run silent.
I, too, would like to see mounting holes. I love how the alphacool top can mount in a drive bay, cause that's where I have my current pump (Eheim 1048 with a couple of custom made aluminum brackets to mount it). I hate to say this, but I have to be honest - I would happily pay more and sacrifice the slight performance gain from your top to get the mounting options of the alphacool.
 

IYIENACE

Limp Gawd
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Mar 7, 2004
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Petra I just placed an order w/ you yesterday (btw thanks for calling to let me know you saved me some $ on shipping) - anyway, hope you get them going soon I'll take 2 please, :D
 

nonlnear

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Bling said:
im curious why the inlet and outlet arent 12.5 mm

Look at the (newly posted) pics of the radiical top The outlet is full bore, but the only way to accomplich this is by destroying the geometry of the pump's impeller chamber. It is possible to run a larger duct from the impeller housing to the outlet, keeping the cross sectional area roughly the same (sort of like the intake on an F-16)), but this would require a much more expensive machining process. Also, having an outlet hole that's too big can seriously degrade the pressure head that the pump can produce. I don't know if this would be the case for a DDC stepping up to a larger outlet, but it's possible.

But the short answer is for simplicity and reduced manufacturing cost.
 

Sneak

Limp Gawd
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Dec 29, 2004
Messages
297
Well I am new to water cooling and haven't even bought a setup yet. This thing caught my eye. Nice and small and I am guessing it is real quiet for the work it does. More to consider but I like this thing. Thanks for all the details Petra's.

Massiveoverkill,
I like the way you have your T line set in the second inlet on that Alpha. Looks nice and neat.
 

MassiveOverkill

[H]ard|Gawd
Joined
Jul 8, 2005
Messages
1,748
Thanks Sneak, set up this way, purging bubbles is effortless. I don't have to turn my rig every which way to get the bubbles out, they eventually bleed out on their own.
 

Petra

Gawd
Joined
Jul 8, 2003
Messages
640
I posted some dual DDC+ loop test data in XS this evening that I figure I should also post here... *copy....paste...bam!*
Me in the XS forums said:
I'm interested to see 2 ddc+ in a loop results as well.
Fine, fine... I caved this afternoon and got all of the test stuff set up again.

Sheesh, the things I do for you guys... :rolleyes: ;)

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 :eek: :
tehTwins.jpg


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:
dualLoop1.jpg


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:
dualLoop2.jpg



Personally, I'm rather impressed by the dual pump 13.8V results... a hair over 2 Gal./min. through a very restrictive GPU block, a CPU block that's more restrictive than the Storm G4, and a radiator. But, that aside, a .5 Gal./min. increase across the board isn't bad at all. Granted, it's a rather expensive .5 Gal./min. increase... however, at least it's a performance increase that would be noticed.

As a random side note due to some other tinkering I was doing, I think I'm going to end up using one of the prototypes in conjunction with my Iwaki WMD-20RLT to help boost the flow capabilities of my CPU block test rig (still a work in progress).
 
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kemist1117

Limp Gawd
Joined
Dec 1, 2005
Messages
506
Petra,

I have 2 of these hooked up to a dedicated comp psu (external rad box) and adjusted the pot to output ~13v which was verified with a crappy old analog multimeter, though the multimeter did say that 12v was 12v so it cant be that far off and the pumps start every time. Did you test in between 12 and 13.8 or do they just not start at 13.8? There is a slight lag from when i turn on the rad box and when the pumps turn on so maybe this becomes more of a problem at higher voltage?
 

Petra

Gawd
Joined
Jul 8, 2003
Messages
640
kemist1117 said:
Petra,

I have 2 of these hooked up to a dedicated comp psu (external rad box) and adjusted the pot to output ~13v which was verified with a crappy old analog multimeter, though the multimeter did say that 12v was 12v so it cant be that far off and the pumps start every time. Did you test in between 12 and 13.8 or do they just not start at 13.8? There is a slight lag from when i turn on the rad box and when the pumps turn on so maybe this becomes more of a problem at higher voltage?
I'll look into that more later today...
 
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