Alphacool have stated they developed the VPP755 in-house, yet it appears remarkably similar to the D5 pumps which we are probably all familiar with. The familiar appearance should come as no surprise given that Alphacool have even stated that the VPP755 is “compatible to D5 mounting places“. This means the VPP755 should be mountable to all currently available D5 tops which is great news as it means end users are not forced to purchase new tops along with a new pump.
Special mention go to one of our long terms sponsors, Aqua Tuning for providing not only the VPP755 review sample, but also the Plexi Esidecke D5 pump top, used during the testing. Without the support of sponsors willing to put their money where their mouth is, and have their products scrutinized and reviewed in a professional, unbiased manner, the ER team would not be able to bring you the factual based reviews which we strive to publish. Thanks Aqua Tuning and Alphacool.
Some of the features being floated about on social media in the weeks leading up to release certainly got our attention with Alphacool claiming the VPP755 is “stronger and quieter than the normal D5” and that “you can control it over PWM or on the knob or both“. Additionally it is said that the VPP755 can be run dry, although we feel a valid reason for doing so might be difficult to justify.
A reliable pump is the heart of any water cooling system, reliable being the key work here and is one of primary reasons that the D5 (and DDC) series of pumps have been the go-to pumps for enthusiasts for over a decade. We have had more compact and less efficient pumps added to the mix in recent times, but no serious contenders have come along that have competed with the D5. Maybe the VPP755 is that contender. We’ll be running our VPP755 pre-release sample through it’s paces and find out if it’s performance lives up to the hype by thorough testing. We’ll endevour to find out it’s performance in terms of flow rate, pressure, noise and control.
The Eispumpe VPP755 comes packaged in a sturdy little box which has Alphacool’s usual white writing and blue logos. At the top of each face in rather small writing we are informed of the contents: “Alphacool Eispumpe VPP755 – Single Edition“, meaning that included is the pump motor only and does not include a pump top which the end user must provide in order to use the pump. At launch, or not long after we would not be at all surprised to find the VPP755 available pre-mounted to an Alphacool Eisdecke D5 Pump Top which we reviewed earlier this year or even one of their top/res combo.
Flipping the lid we found an o-ring seal placed on top of the pump motor within a protective layer of bubble-wrap.
We didn’t expect anything fancy in terms of packaging. The way in which the VPP755 is packed meets our expectations and does a good job of ensuring the pump arrives to the purchaser in perfect condition.
After removing the bubble wrap we got our first look at the VPP755 and immediately the gun metal grey painted finish on the motor cover got out attention. The grey finish has a slight speckle in it and is silky smooth to touch. Alphacool have indicated that they will be releasing alternate color motor covers so you match your pump in with your color scheme. The cover adds a slick, professional looking finish to the VPP755 pump and we’re sure you will like it as much as we do.
On the bottom of the cover are some “Technical Data” about the motor, which are not to be found anywhere else, at least not with our review sample, which had no specs on the box and did not have an instruction/information sheet enclosed.
Let’s list that Technical Data provided and briefly comment on each. We’ll delve much deeper into each as we work through the testing process.
1700 – 4500 RPM – good low range for silent builds, 4500 is lower than the D5’s 4800.
8 – 13 Volt DC / 14 Watts – pretty standard Voltage range for our water cooling pumps to operate at, however for a “performance pump” 14 W does seem on the low side.
Starting 12 Volts DC – bit worried that pump may not start when set at lower power/rpm speeds, but this depends on the control which has been implemented.
IP32 – Ingress Protection against solid objects over 2.5mm and protected against falling drops of water.
Lift Height 4.0m – not our preferred method of rating a pump’s performance.
Max 65°C Fluid Temp – perfect, as coolant temp above 45° are not recommended for water cooling systems anyway.
As seen in the above image, some laser etching has been done on the cover base for the logo/model and serial number of the pump. Again we find it very pleasing that Alphacool have made the extra effort and the result is a very smart looking pump.
Also a feature on the base is the “Vario style” speed adjuster, which is scaled 1 to 5, with 1 being the lowest setting and 5 is the highest. We’ve seen claims that the manual adjuster can work in conjunction with the PWM control that the VPP755 also features. We’ll have to see about that and delve deeper into both control methods during testing. For now it’s good to know that manual pump speed adjustment is present on the VPP755 as well as featuring PWM control.
The cover is removable on the VPP755, as one might expect given that different color covers are going to be made available, however removal is not as simple a process as it is on a D5. There are 3 clips on the motor side which lock the cover in place and getting all 3 unlatched at the same time is challenging, although doable.
Apart from changing the cover to a different color, the only other reason one might need to remove the cover is for doing a custom wire sleeve job, so most users will never have to worry about cover removal.
With the cover removed, the circuit board is on display. While all the soldering all looks good, the placement of the board retention clips is a little unusual. This image shows one is located directly on a trace and another is on solder spot. Also unusual is the apparent effort that has been made to conceal the chip identity evidenced by the scratch and scuff marks on top of the chip.
Wiring & Connectors
You may have noticed some cable sleeving on the wires in the previous images, and yes the VPP755 does indeed come with it’s wires pre-sleeved, sort of.
The total length of usable wiring is ~50cm from pump cover to the connectors, of which ~30cm of black sleeving has been fitted on the pump side before the power wires and control/monitor wires split to separate connectors.
After the sleeving ends and wire groups split, each group of wires has black heat shrink fitted over the wires which is certainly much more easy on the eyes than exposed colored wires. While far from perfect Alphacool have made an effort with the wires and we expect most purchasers will be happy enough to not bother doing their own custom sleeving.
We assume this “extra” 3 pin connector is for sending an RPM signal to a fan controller for rpm readout while the 4pin is connected to the motherboard header for both PWM and RPM functions OR the other way around. Whatever the reason it seems an afterthought as evidenced by the blue PWM wire being longer due to the second RPM wire being added and the short wire to the 3 pin was not heat shrinked like the others.
On the outside the VPP755 impeller looks very similar to that of the D5.
BUT….when we look into it we start to notice the differences. First of all there is that white washer which acts as a retainer for the impeller and keeps it almost fixed in position, although there is still a short amount of free play in the stroke.
Once that locking washer is removed the impeller can be slid off the shaft and the major difference between the D5 and VPP755 impellers can be seen. In the following image note the retaining washer is back on the shaft and there are two additional washers now in view. Do not lose either of these because one goes at the base of the shaft (before the impeller is put on) and the other is fitted at the top of the impeller (just before the white retaining clip washer).
The VPP755 clearly has a cylindrical shaped impeller and matching housing while the D5 has a cone shaped one.
Pump Top Installation
I am not going to go into detail here about fitting the VPP755 to the Eisdecke D5 Pump Top, as I did a step by step install for the Esidecke review. Using that installation guide and the seal provided with the VPP755 we had no problems and it was leak free on each of the 5 times we mated the 2 products together.
D5 Top Compatibility
There are a couple more subtle differences between the VPP755 and a D5 and as we found out, these last two differences could mean that the VPP755 is in fact NOT compatible with other D5 tops.
It may be worth noting that the VPP755 is slightly shorter in overall length than a D5, although this will not not affect pump top compatibility. That ~8mm could make all the difference between fitting or not in tight spaces, so we see this as an advantage in the VPP755’s favor.
Firstly the height of the shoulder of the VPP755 is ~1mm longer on the VPP755. On some pump tops this is where the o-ring seal must be placed, and with the lengthened shoulder the seal may not make contact between pump and top, therefore not creating a seal.
I did try to measure the difference, but I was not confident with the result to say for certain the exact measurements and therefore the difference between the VPP755 and the D5. Here was how I attempted to measure (D5 in the image). The best I can offer is to say that the VPP755 shoulder height is more than that of a D5 which could effect the ability to seal when fitting to a D5 top other than the Eisdecke D5.
Similarly, it appears as though the impeller height protruding above the shoulder is slightly longer on the VPP755. An actual measurement was impossible to take, so again you will have to have faith when I say it is slightly longer. So what does a slightly longer impeller mean anyway? Well if the impeller is touching the the volute (inside of the pump top) because it is too long the pump is unlikely to spin up, or at the very least be dragging against it resulting in lower rpm and therefore weaker pump output while risking the pump circuitry overheating – not ideal.
So is Alphacool’s statement that the VPP755 pump is “compatible to D5 mounting places” accurate? Unfortunately for the end user it is not. The shoulder height and impeller length differences means that some other manufactures D5 tops will not be compatible with the VPP755 pump. We set out to find which are compatible and which are not and our findings are that tops which need the o-ring fitting onto the shoulder are less likely to be compatible, but that was not always the case.
Unfortunately we don’t have every top ever made on hand for a complete compatibility list, but below are the tops that we physically tried to fit the VPP755 to. If a seal was thought to be made then a wet test was conducted. Hopefully we can update this list in the future as more tops become available.
Compatible Pump Tops for VPP755 pump.
Alphacool Eisdecke D5 Top – wet test pass, pump vertical and horizontal.
Barrow D5 Top – wet test pass, pump vertical.
Bitspower D5 Mod Top V2 – wet test pass, pump horizontal.
Bitspower D5 Mod Top “S” Model – wet test pass, pump vertical.
EK-XTOP Revo D5 – wet test pass, pump vertical.
NON Compatible Pump Tops for VPP755 pump.
EK-D5 X-TOP CSQ – no seal contact, tried thicker o-ring and cracked the retaining collar – no wet test. Probably will work with thicker o-ring and don’t crank down “too hard” on the retaining collar screws
EK-D5 Dual TOP G1/4 CSQ – no seal contact, no attempt with alternate o-rings made.
Monsoon SAP – sealed well and wet test commenced but after running for ~2 minutes (pump vertical) noise erupted from inside the pump. Looks like contact between impeller and volute during operation, shaft kept spinning and flicked off the white retaining washer and flat washer underneath it. It is possible I did not put impeller retaining washer back on properly, but very unlikely as pump had been in operation for many hours after it was re-assembled following the photo shoot. Has run smoothly for a few hours since the “incident”.
Next up, Controlling the VPP755