Posts Tagged ‘Koolance’

Koolance PMP-500 Pump

Posted: December 13, 2012 in Pumps
Tags: , , , , ,

Welcome to my review of the Koolance PMP-500, a new monster pump from Koolance with really impressive pressure specs.    I was instantly interested in getting my grubby little hands on one of these ever since I saw it come out just a couple of months ago.  Pumps and hydraulics has always been more fun for me than thermal testing, so I was naturally interested in this new beast of a pump.  While we do already have several great options, the competition between pumps is somewhat limited compared to other water-cooling products.  This one per the specs looks very interesting, so the question is, how does it size up in terms of size, pumping power, cost, and noise relative the other popular options like the PMP-450.

A special thanks to Tim from Koolance for sponsoring the parts used in this review.


Manufacturer Description & Specifications

The Koolance PMP-500 offers a high flow rate and very high static head pressure at just 12V. A mounting bracket is included.

  • Maximum Flow Rate: 16L/min (4.2 gal/min)
  • Maximum Head Pressure: 7.5m (24.6ft)
  • Motor: Brushless DC
  • Power Consumption (at max): 32W
  • Voltage Range: 6 to 12 VDC
  • Maximum Temperature: 60°C (140°F)
  • Electrical Connector: 3-pin fan header with tachometer speed signal
  • Hose Connections: G 1/4 BSP Threads
  • Noise: Less than 50dBA
  • Weight: 454g (1lbs)

Please note, the CTR-SPD12X2 and TMS-205 are unable to support this pump due to power constraints. For compatible speed control theCTR-SPD1224 is available.

Weight 1.20 lb (0.54 kg)
Dimensions 2.80 x 2.40 x 2.40 in (7.11 x 6.10 x 6.10 cm)
Max Flow Rate 16L/min (4.2GPM)
Max Power 32W
Max Static Head 7.5m (24.6ft)
Max Temperature 60°C (140°F)
Native Hose Connection G 1/4 BSP Threads
Speed Knob
Tachometer yes
Type Magnetic Centrifugal
Voltage 6-12 VDC

So, the specs are mighty impressive for sure in terms of pressure head.

Welcome to another bay reservoir review, the Koolance RP-401X2.  I thought the RP-402×2 was compact for two pumps in a double drive bay size, but this model takes that concept up another notch.  The PMP-400 (DDC3.25) pump motors are very compact and Koolance figured out a way to put not only one, but two motors in a single drive bay reservoir that retains much of the same multitude of options as the 402×2 flavor. You can run one pump only and share both reservoirs, you can run two pumps in separate loops, or you can combine the two pumps via their serial kit for extreme pumping power.

A special thanks to Tim from Koolance for sending over the sample to review.

Packaging & Accessories

First let’s have a look at the box opening:

It comes in a longer brown box as shown here with solid foam protection along the sides

Having done a few drive bay reservoir reviews, it should be noted that not all come fully assembled.  The Koolance RP-401×2 is of the fully assembled and ready for pump status types.  It also has a block off plate installed on the left (P2) side and plugs ready for a single pump installation.  This keeps the number of loose parts down to a bare minimum and should save some time up from on the assembly front.

No major assembly required, ready for single pump right out of the box

It does also come with what I would call a quick guide.  It’s a smaller double-sided black and white four page guide.  Don’t expect a ton of detail here, but the guide is well illustrated and covers the key installation areas well although I would have liked to see some added info on bleeding. You can download the electronic and color version of the manual here for a more detailed look.

In general the package was very complete short of barbs and the serial kit.  Those items will have to be purchased separately and are an added cost.  The reservoir/top does come fully assembled with the necessary port plugs and pump block off so you can run one or two pumps as desired and there isn’t any assembly needed which is also nice.  The Packaging and protection also seems good and arrived in good condition.

Welcome to my second in a series of CPU block tests I’ll be working on for the new i7-2600K processor…compatible with the 1155 socket is the Koolance CPU-370. This is the latest in Koolance’s CPU block refinements building upon the CPU-360 as well as now including a 1.5mm nozzle plate in addition to the 2.0mm nozzle.  My old EK supreme was king of my Q6600 block round up and still working very well on my i7-2600K, however that was a couple of years ago, and block have improved.  Since that time Koolance had introduced the more refined CPU-360, then the CPU-370, and now the CPU-370 with a 1.5mm nozzle plate option.

I would like to thank Tim from for providing this sample.   Thanks!!


  • Microchannel copper cold plate (.25mm fins, 0.30mm channels)
  • O-ring sealed impingement plate
  • Brass Top
  • Steel Hold Downs and back plates for Intel (775,1155,1156,1366) and AMD (AM2,AM2+, AM3)
  • G 1/4 BSP threading (3/4″ OD Compression Compatible)
  • 1.5mm and 2.0mm stainless steel nozzle plates included (2.0 Installed)
  • Nickel-Plating to prevent copper/brass oxidation
  • Bowed Base

Packaging & Contents

The first thing to catch my attention of the box was the heavy weight. For being just a CPU block it was heavier than expected which is due to the all metal construction and multiple plates included.  Packaging is in Koolance’s typical black box and white lettering theme and was very well packaged and shipped in your standard packing peanuts style…everything arrived safely and well protected.

Opening the box you are greeted with the instruction manual with layers of parts below. You can check out the manual by downloading it here by clicking on the “Manual” button.  It’s good getting started manual that should be sufficient for most users.

Contents are separated by layers of cardboard and plastic bags

After emptying the layers of contents, this is what you end up with:

Box Contents

The upper hold down is for AMD, and it comes with the Intel hold down installed on the block.  A pleasant surprise is not a only backplates for each CPU type, but also plates that are cut from solid and thick (1/8″) steel.  The white piece to the middle left above is a nice thick insulating rubber/silicone like pad that should do well to prevent any shorting out of contacts on the back of the MB.

Within the bag of goodies is the following:

Parts Bag Contents

It includes some rather over-sized thumbnuts, springs, TIM, Studs, 1.5mm nozzle plate, washers, torx wrench, and aluminum/copper foil for attaching thermal probes to your block for temp monitoring.

Short of barbs, the package is extremely complete for both Intel and AMD users.  I personally tested both nozzle plates for restriction, but decided to go with the 1.5mm nozzle for my first round of thermal tests since it was still fairly low in restriction.  Overall, I was very happy with the packaging & parts package…all you really need to buy separately is a set of barbs.

Probably one of two most popular pumps in all of watercooling, the Koolance PMP-450 is a D5 Vario pump and packs a very strong amount of pumping power while retaining it’s built in variable speed controller.  There are multiple flavors of this pump and I have personally used the D5 series ever since my first loop watercooling several years ago.  Koolance has taken this very popular variable speed pump and added what it has been missing for far too long…an RPM sensing wire.

I would like to give special thanks to Tim from Koolance for sponsoring this powerful pump:


Koolance offers two flavors of the PMP-450 pumps.  One is the subject PMP-450 pump with variable speed control and the second is the PMP-450S pump which is fixed and designed to run at high voltage and higher speeds.

The pump comes in a factory box as a “Bare Pump” type product.

Box indicates it is a Laing D5-38/810 vario with 1/2″ barbs

Well packaged bare pump, no accessories

Both flavors of the pump share the exact same pump housing with the exception of the rear cup in which the PMP-450 has a hole where the variable speed control protrudes.

Variable speed controller and a BLUE RPM WIRE!!!!!

What’s different about the Koolance Brand pump?

There is one thing that I had always very much missed with various other D5 Vario pumps, and that’s the RPM sensor wire.  I’ve have several non Koolance brand variable speed D5 pumps now and none of them ever came with this very valuable feature.  As far as I know, Koolance is the only one to offer a variable speed Laing D5 that comes factory with the blue wire 3 pin RPM sensing wire.

Why is RPM sensing important?

RPM readout provides two important bits of information:

  • Pump and Loop Health Indicator – Having the ability to read RPM is a good way to see the pump is functioning as it was designed.  Sudden changes in RPM are indicators that either something has changed in the loop (IE a block is plugging), or that the pump is experiencing problems.  Without the ability to monitor via RPM, you are left with very little indication.
  • Pump Failure Shutdown – RPM is likely the easiest method of setting up an emergency pump shutdown routine.  Most motherboards and bios tools have some ability to set a minimum RPM level for the CPU fan header.  While this was originally intended to serve as a failsafe for CPU heat sink fans, it also works for pumps that have RPM sensing abilities.  While the D5 series may very well be the most trusted pump in all of watercooling, it’s always good practice to have a failsafe.  Running two pumps in series can give you redundancy, but what happens if you have a single pump and the pump fails…bad things can happen.  I personally have had an instance where I was working on my case and accidentally bumped a loose molex connector only to have the pump quit working.  My 8800GTX video card loop actually melted the acetal in my VGA block and the tubing had deformed to the point that it was nearly ready to burst.  Luckily I was right there looking and noticed the water boiling in my loop after getting a sense of some odd smell.  Had the tubing burst, surely there would have been disaster.  Having had the pump on a shutdown routine, would have prevented that.

Soo…I’m extremely happy that Koolance has now provided us with a D5 Vario WITH RPM sensor!  That’s awesome!

With that, let’s look around the pump.  It does come with a nice steel base which lifts the pump off the ground.  This metal base is ideal for sitting on a decoupling material since there will be no issue with heat.

1/2″ barbs come factory, no need to install a top for larger tubing

Now, let’s have a look on the inside, first and overall parts picture:

Tool-less disassembly reveals the goods, Ceramic/Carbon ball bearing, spiral volute

Another nice features of the PMP-450 is the completely tool-less ability to take the pump apart.  The pump is held in place by the large ribbed collar which simply unscrews with the twist of the hand.  The large o-ring you see sits in the volute housing and seals the metal pump housing to the thermoplastic volute.

At the heart of the pump and common to all D5 & DDC pumps is the very desirable ceramic ball bearing which mates up with a graphite impeller bearing cap.  The one point is the only point of contact and wear and makes for an extremely long life.  I have yet to see one wear out unless someone accidentally ran one dry.

The other perhaps not so obvious feature that makes a very large impact on the pump is the metal pump housing (Canned Spherical Motor).  There are two benefits to this.   One is the cooling capability and heat transfer that the metal housing provides.  Unlike it’s brother DDC series which uses a plastic housing and resulting heat buildup, the PMP-450 and it’s metal house serves extremely well to watercool the pump.  This does lead to more heat entering the water, however the cooling ability is beneficial to the pump electronics in keeping it cool.  The other benefit to this canned housing is how the metal canning creates a water tight seal around the motor housing.  While the pump is mounted any failure in the o-ring or other possible leak will generally have a very difficult time ever finding it’s way into the electronics of the pump.  I think it’s the above two reasons that make this pump one of the most durable water cooling pumps on the market.  They are water cooled, and have built in leak protection.

Easy assembly

So the pump overall has some real durability enhancing features, it has an RPM sensing wire, and very easy to take apart and clean for maintenance needs.

About the only downside I can think of is the larger size and lack of decoupling pad.  Some folks also have noted that the barbs are slightly over-sized and take a little more force to install tubing on.  I consider oversized barbs a big benefit in general because it generally leads to much lower chance of leaks.  Also decoupling material such as a piece of egg crate works perfectly fine.  I just wouldn’t recommend bolting the metal stand to the case if possible.

12V Test Results

Detail (Retest Done 12-15-12)


Following my usual pressure vs. flow rate testing, I came up with the following family of curves at 12V.  Generally settings 4 and 5 would be good options for average to higher restriction loops and settings 2 and 3 for very low restriction loops.  Setting 1 is really a bit too underpowered to maintain acceptable flow rates, although I would encourage anyone to try.  Note that my setting 5 is actually max and setting 1 is min.  I figure anyone that is operating at 5 likely has the knob turned to the max which is very slightly more than 5, etc.

Setting 1 through 5. Pressure is the solid lines, Watts is the dashed lines.

12V vs 24V

You may have noticed that the pump is perfectly capable of operating at higher voltage up to 24V.  This may lead you to believe there would be a significant performance difference between 12V and 24V.  I tested that below:

Setting 5 12V vs 24V, very very minor benefit with low restriction loops

Unfortunately there is not much benefit to using 24V on the PMP-450 pump.  Up to about 1.5GPM there really was no measurable benefit, on the contrary because it was consuming about 1-2 watts more.  I would not recommend purchasing a controller to operate this pump beyond 12V, it’s just not enough difference to bother with.

Performance PMP-450 vs PMP-400 + Top

While tops don’t help much on the PMP-450 pump because the factory top is already very good, they do help a lot on the PMP-400.  Soo…many have folks choose the PMP-400 for it’s slight performance advantage.  Here is that comparison:

The difference here will not add up to much temperature difference, but the PMP-400 with top is a slightly stronger pump for our more restrictive water cooling loops.


One thing you should also consider with this pump is it’s relative size.  It is generally bigger than the PMP-400 or other DDC pump at least until you put on a top and lift the PMP-400 to provide more cooling.  Then they are comparable.

Size Comparison

On the left is actually the 450S model, but both (450 & 450S) are the same size so I reused the picture.  Without the lifting base, the PMP-400 is a fair amount more compact.  Size is something you’ll want to consider.  Also note that the inlet port and outlet ports are reversed between the two pumps.  The PMP-400 with top accepts the in from the top, where the PMP-450 accepts the in from the side.  Depending on your tubing configuration, you might have a preference one way or the other.


The pump is extremely quiet, particularly when installed in an acetal aftermarket top.  Check out the noise data in my pump noise round 1 piece where I tested both the stock top and after market top.


Not a huge deal as I think the differences are relatively small, but the PMP-400 when coupled with an aftermarket top will produce slightly more pumping power per watt than the PMP-450, but that is only after the PMP-400 has had the factory top (with an inlet elbow) removed.

Not quite as efficient as a PMP-400 with top

This is pretty minor when you’re talking about 20 watts worth of heat, but something to consider if you’re looking at running something extreme like triple pumps in series.  The PMP-400 with top is a bit more efficient by a few watts depending on the restriction.


  • Extremely reliable long lasting pump
  • Canned metal housing protects electronics from leak damage
  • Canned metal housing cools the pump motor very well
  • Factory Top performs very well, no inlet elbow
  • Factory Top comes with 1/2″ barbs
  • Koolance brand includes an RPM sensor wire, yes!!
  • Factory speed controller built in (no need for voltage controller to reduce speed)
  • Easy tool less entry
  • Cost – When compared to a PMP-400 plus top
  • Very Quiet
  • Larger in size
  • Not quite as powerful as a PMP-400 with top
  • Not quite as efficient as a PMP-400 with top
  • No decoupling pad or accessories (bare pump)

So there are some give and takes when compared to the PMP-400 series, but you’ll find the user base very much split out there.  I believe the durability, long life history, and cool operation are all very desirable features many prioritize highly.  I like this pump very much, and particularly like it now that Koolance has provided us with the RPM sensor.  You really can’t go wrong with either the PMP-450 or PMP-400 pumps, I use them both myself and can’t really pick a favorite because I see benefits in both models.  The nice thing about the PMP-450 is that you get a speed controller and a good 1/2″ compatible top factory out of the box.  You also get a pump that runs very cool and has a long history of reliability.  These are all very good qualities and I highly recommend it.


Welcome to another pump speed controller (CTR-SPD10), and before you pass by thinking you can get the same thing from any fan controller, take a closer look.  This little analog controller is also built with a transformer so you get slight “Overvolt” capabilities as well as undervolting.  I used these controllers in my pump noise testing because of this ability and they are really well suited to driving the PMP-400  or other DDC pumps that otherwise don’t have speed control.

I would also like to thank Tim from for providing this sample.  These controllers gave me the ability to complete my noise testing in complete silence (my test PSU clicks very loud when switching) Thanks!!


The controller housing notes the range of use is 7.5V to 12.7V out at 25W max.  This is really ideal for the PMP-400 or similar fixed pump.


The unit is compact in size and could be installed in a variety of locations.  It comes with a piece of velcro as one option and also a pair of screws where you could solidly mount the face by drilling three holes (one for the control knob and two for the mounting screws).

It is just over 3″ long and about 1-3/4″ wide and just under 1″ tall.


Input is a 4 pin molex, output is a 3 pin header


The control knob is located up front and has a small phillips slot


I figured the most common use of the controller would be controlling a DDC pump such as the Koolance PMP-400 pump, so that’s what I used to test the controller.  I wanted to see what the actual voltage range was when feeding it exactly 12.0V while under load of the pump.  I also wanted to take a look at the pump performance and rpm to see what changed under this control.

Minimum Voltage As Measured to pump = 7.90V

Maximum voltage as measured to pump = 13.28V

Overall, this is a good range of voltage control for this pump with the exception of the maximum being a touch high.  I have found that the PMP-400 pump doesn’t like to start beyond 13.0V, so you will need to be careful to dial down the controller just a bit to ensure starting.  12.8V is about the maximum overvolting that I would consider, so that’s what I used in testing the pump.

I did my normal pump testing to measure dynamic head pressure (outlet – inlet) while increasing restriction and measuring flow rate as shown above.  I also adjusted the pump voltage via the Koolance CTR-SPD10 to several fixed voltage ranges to see how the performance is impacted.

Performance Pressure vs. Flow Rate Summary, up to a 15% pressure head increase

Here is a look at the RPM or speed of the pump for noise reduction.

Speed (RPM) comparison, up to a 35% RPM reduction


This is a great little pump controller particularly for the many pumps which are fixed in speed such as the PMP-400 or other DDC pumps.  This controller essentially gives you variable power and noise control over a pump that is otherwise fixed.  In addition it gives you the option of over-volting the pump due to it’s unique transformer.  While there are many fan controllers that could also reduce speed, this is the only option I know of that can go down to 8V and UP to 13V.  Most fan controller will have a maximum below 12.0V because of losses within the fan controller.


  • 25 watts capacity is ideal for the PMP-400
  • Over-volt (13Volts) capability can increase pump pressure head by up to 15%
  • Under-volt (8 Volts) capability can reduce pump noise for ultra silence
  • Compact size make is fairly easy to install in a variety of locations
  • Simple operation up and down


  • Maximum volts can exceed pump startup limit (user needs to reduce slightly from maximum)
  • All manual control only

Overall I am very happy with this controller, particularly for it’s unique ability to not only provide a solid 12V which most fan controllers can’t do, but also to increase it for an extra bump in performance.  I would suggest installing extra cooling on pumps that you are considering overvolting, as any sort of voltage increase will also increase heat output of the pump.

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