Unboxing, Overview and Disassembly
The test sample was sent by Aquatuning, and thus we will begin directly with the product packaging:
Very minimal packaging here, with a simple cube design akin to what Alphacool does with the rest of their pump only products (without tops). The company and product name are really all you see here. No flaps or seals either, so there is no way to guarantee the product has not been opened before to delivery. Open it up and you see an O-ring as well as the pump inside a sleeve of bubble wrap- all tightly packed inside the box. Overall, packaging can be improved and this is not up to the standards Alphacool has set with the rest of their “Eis” lineup of products.
The pump itself is really similar looking to the Laing D5, and that is on purpose. But look closer and the differences come to sight. The pump housing is a glossy gunmetal grey aluminum cover with specs printed on it, and we see this has a control knob akin to the D5 Vario. Note that there are settings 1-5 here too, and it comes set to 5 out of the box as seen in the picture above (the open end is not pointing to the active setting). There is a closed rotor here which is nice to see, as it is more expensive to make compared to open rotors (such as what Swiftech used in the MCP30/MCP50X) but offers ever so slightly better performance for the same design. The rotor housing is also different, and is actually held in place by a plastic washer:
That white washer aside, there are 2 other black plastic washers on the ceramic shaft bearing on which the rotor is held in place. Alphacool claims running the pump dry will not affect it, although there is really no reason to do so and I recommend treating it as with any other pump and not run it dry. The rotor once removed helps compare the VPP755 with the D5:
and re-assembled (excuse the pumps being the other way round in the first image below):
So we can clearly see the rotor on the VPP755 is cylindrical compared to the more oval rotor in the D5, and the pump cavity having an opening accordingly. A shaft bearing on the VPP755 vs a bearing ball on the D5, both made of ceramic, and the exchangeable cover on the VPP755 vs a fixed body cover on the D5 are the other obvious differences. Alphacool promises different covers out of the box and also sold separately to help color match this with the rest of the build, and this replaces aftermarket D5 housing mods thus. The astute ones here will note that the VPP755 is also shorter than the D5, which by itself is good in that it will occupy a smaller footprint once installed. However, the collar near the rotor where O-rings seal in place when installed is a different proportion to the rest of the body and this can cause compatibility issues with some D5 pump tops. We will get to that soon.
Let’s take off that cover and see what’s ticking inside, shall we?
In order to do so, you will need to pry loose three plastic tabs on the plastic body similar to how some keyboards and mice are held together. A small, thin, flat driver will be handy here and be careful to not pry too much lest the tab break off. The cover itself is sturdy aluminum and will do together fine. Once loose, you will have to push the cover outwards and away, but will face resistance from the heatshrink on the pump cable so this is not going to be a simple task for those wanting to replace the covers themselves once the option arrives. On top of it, you will have to remove the pump connectors as well. In order to examine the PCB, I could just have the cover along the pump cable itself and not removed completely:
The motor is on the underside, and the copper wiring can be seen headed towards and soldered on the PCB, which itself has multiple layers. The control knob looks like a potentiometer that acts like a voltage divider, and this is where I will tell you that despite what the specs say the pump does not have true PWM control. It is disappointing, but let’s see how it works out in practice when we get to pump control. Alphacool claims this is because of the issues of some motherboard makers as well as PWM device makers not sticking to Intel PWM 1.3 spec which is fair but an excuse nonetheless. They have done a good job of making it hard to identify all the components, including having PET heatshrink on the capacitor and remove the capacitor label itself. The only easily identifiable components are the Din-Tek DTM4600 MOSFETs. Soldering was okay in some areas and shoddy in others with massive solder balls seen.
There are indeed 4 wires that come off the PCB that go into the pump cable:
The pump cable has black heatshrink as mentioned before, and the sleeving also is black in color which is nice. The sleeving was applied very loose although it doesn’t hurt much and does the job of hiding the wires inside. Not much to complain here considering the D5 has no sleeving at all. The power itself is fed directly from the PSU, hence the full size MOLEX connector. I would have liked to see SATA instead, 14 W is fine here. “PWM” control and RPM sensing is provided by the 4-pin fan connector and the RPM cable is passed-through to a separate, third 3-pin fan connector. I can think of one application here- having a separate connector provide the PWM signal using the RPM readout and have the RPM only connector on the CPU_FAN header in case your motherboard needs an RPM readout and has no way to ignore a zero RPM signal. But the two headers are very close to each other, and one might as well just use the CPU_FAN header for PWM signal and RPM readout so I am confused about this.
So let’s talk about usage. The pump in this configuration needs a top to be used, and Alphacool claims it is compatible with all D5 tops. Okay then, that is a bold claim considering there are actual physical differences but let’s see:
The classic Laing D5 top works just fine with the VPP755. Although given the choice, I recommend going with aftermarket tops with options of threaded ports, aesthetics and more.
Alphacool’s tops also work to no surprise. This includes the built-in top in the BAY Station bay reservoir and the Eisbecher cylindrical reservoir. Alphacool also has standalone D5 tops called the Eisdecke, and those have the same design meaning they will presumably work as well.
Not shown here is the XSPC D5 bay reservoir but it worked fine as well, I was using it for testing too. So far so good, but then EK came along:
The EK-XTOP CSQ clean top did not work at all, there was a physical gap between the top, pump and the mounting bracket owing to O-ring collar compatibility (or lack thereof). The newer EK-XTOP Revo D5 top was a mixed bag, I had a small leak even with the best of fit and I know of at least one other person who had no leaks. What I am trying to tell you here is that even with just 5 different D5 top designs here, I had incompatibility with 1-2 of them. As such, I can not accept Alphacool’s claim of universal compatibility with all current D5 tops and brackets. Sure, there is leeway in the definition of “current” tops here but in the end the customer will be the one with regret if he/she has compatibility issues. So please be aware of this potential issue. I recommend treating the VPP755 as a separate pump altogether and go with guaranteed tops only. The Alphacool D5 tops are really good thankfully and have enough options to suit most, if not all customers.
(Update: November 7, 2016: Alphacool tells me that they have tested compatibility of the VPP755 with D5 tops from Alphacool, Aquacomputer and Heatkiller. So there is an extrapolation on their part regarding universal compatibility. However, they also mentioned that Xylem/Laing made a small physical change to the D5 itself in 2011- so much so that tops made for the D5 pump prior to this information are not compatible with the VPP755, and barely compatible with newer D5 pumps if at all. As such, Alphacool is saying here that their VPP755 should be compatible with all D5 tops that are new and catering to the physical change in the D5 pump.)
Let’s now take a look at how the pump behaves and performs on the next page.