Navigate to:


The D5 pump from Laing/Xylem is easily the most popular pump in the DIY watercooling field, with nearly every brand selling their version of the pump (fixed 12V, 12 V + voltage control, Vario, PWM, 24 V + voltage control) but differentiating themselves with a sticker on the back and their custom tops (standalone or reservoir mount). Generally, however, the pump is identical among the various brands for the particular option used. A D5 PWM pump from, say, XSPC, is the same as a D5 PWM from Swiftech. Despite my preference for everything PWM generally, this is one case where I would go with a D5 Vario if I had the option. For whatever reason, Laing programmed the D5 PWM to run at an impeller speed corresponding to 60% PWM duty cycle when there is no PWM feedback signal provided, and it does not follow the PWM specifications Intel has provided for motherboard makers as part of the CPU_FAN and CPU_OPT PWM headers. The few PWM controllers that are out there also follow this generally, and this means that controlling a D5 PWM pump can be a hit or a miss. Today we take a look at EK’s new XTOP Revo D5 top and, more interestingly to me anyway, their take on the D5 PWM pump which is not just a rebranded Laing D5 PWM. Thanks to Derick for arranging the test sample.

EK sells the D5 PWM G2 by itself, and also the XTOP Revo standalone tops in acetal, plexi and a dual pump top version separately as well. They also sell a complete version with pump and top pre-installed and this is what I requested. As such, let’s take a look at the specs of the XTOP Revo D5 PWM (inc. pump) from the product page:

Technical specifications:
– Motor: Electronically commuted spherical motor
– Rated voltage: 12V DC
– Power consumption: 23W
– Maximum pressure head: 3.9m
– Maximum flow: 1500L/h
– Maximum system temperature: 60°C
– Materials: Stainless steel, PPS-GF40, EPDM O-rings, Aluminium oxide, hard coal
– Power connector:  4-Pin Molex- and 4-Pin PWM FAN connector

Operational Regime:
– PWM duty cycle: ~ 20-100%
– Default behavior: Runs at 100% duty cycle when no PWM feedback signal is present

– EK-XTOP Revo D5 PWM (incl. EK-D5 PWM G2 pump motor)
– Mounting clip with rubber insert
– Self-adhesive mounting hole pattern sticker
– Mounting mechanism (incl. required Allen keys)
– Installation manual

Made in Slovenia – EU!
Pump motor made in Hungary – EU!

There are versions of this pump with the acetal top, plexi top and also the dual pump top version, and I got the acetal top version here. In hindsight the plexi top would have made more sense as we will find out soon, but functionally there is no difference between the acetal and plexi tops. The main change here compared to EK’s earlier D5 tops is a round top design compared to the square design that they and pretty much everyone else adopted. This means that the top can occupy less space relatively, and also there is now a smoother transition going from reservoirs with round tubes to a D5 pump with a round top as well. In fact, here’s a quick visual look at what I meant courtesy the EK XRES D5 reservoirs:

Back to the XTOP now. Another change is in the mounting where it is a lot smaller in footprint as well and this is something we will take a look at in more detail soon. The third big change is the pump comes with a “pump body” aftermarket part included with vibration dampening built-in whereas the previous such accessories from EK (and others) were more for aesthetics than anything else.

The D5 PWM G2 is, well, the same as a standard 12 V D5 PWM from Laing with some modifications to the PWM program to the motor. Instead of running at a 60% duty cycle equivalent with no PWM feedback signal (if you have not plugged in the PWM cable to an active PWM controller, for example), this runs at full speed which will make filling and bleeding a loop easier provided you have accounted for air in the loop to escape. Another change EK advertises is a larger range of RPM control with a different RPM response curve over the same PWM duty cycle of 20-100%, and of course this is something we will see for ourselves. I just happen to have an XSPC D5 PWM here for comparison.

Before we go the next page for a detailed overview, a reminder that all EK products carry a limited 2-year manufacturer warranty including this one. Let’s carry on to the next page now.

Pages: 1 2 3 4