Posts Tagged ‘pmp-450’

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:

Overview

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)

Koolance-PMP450-PQdetail12V

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.

Size

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.

Noise

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.

Efficiency

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.

Conclusion

Pros
  • 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
Cons
  • 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.

Cheers!
Martin

Welcome to my very first standardized round of pump noise tests in my continued pursuit of silence (The primary reason I water-cool).  This round will be much more controlled with an emphasis on consistency between pump tests.  Anything with the pump noise Round 1 will have the same test conditions.  Pump noise is normally not a concern for folks with higher speed fans or for installs where the pump is allowed to float freely avoiding vibration transfer.  However,  solid mounts and/or when users begin dipping below the 1000 RPM level are conditions where pump noise can become the primary noise annoyance.  This testing effort is looking at a variety of DDC/D5 series pumps in various flavors and tops measure dbA relatively to flow rate on a low restriction loop.

I want to give a huge thanks to my many sponsors.  Tim at Koolance.com, Gabe at swiftech.com, bmaverick, and XSPC.biz have all sponsored in some way.  Without their generosity this test would not have been possible.   Tim from Koolance.com sponsored most of the items in this test including the pump controllers used on voltage regulated pumps.  Thanks!!!

Test Conditions

Test Setup, sorry for the poor phone picture, camera in use.:)

This round will use a low restriction CPU block only type loop that includes the Danger Den MC-TDX, XSPC RS120 radiator, King Instruments Flow meter, 1/2″ tubing, and a custom 3″ ABS reservoir with 5/8″ fittings.  The loop also contains some very low restriction brass globe valves for easier swapping between pumps.  I chose a low restriction loop for this round so I could get a greater number of data points. I may later attempt the same for a more restrictive loop although you could cross correlate with RPM values to PQ pump curves if desired as well.  Some noise is actually generated at the restriction points (blocks) as well, but this will be a good relative test between pumps.

I am also testing in two decoupling scenarios.  The first is a near ideal soft foam free floating type test, the second is direct metal contact.  This gives you sort of a worst/best range of noise.  In my earlier testing I found that thinner foam neoprene would fall somewhere in the middle.  Other options such as rubber washers/grommets would also fall in between and likely a bit more toward the worst case condition.  This best/worst case should give you a sense of possible noise range which is fairly dramatic in most instances.  This will also likely emphasize the importance behind decoupling pumps.

For relative scale, I’m including approximate noise level tests from my Gentle Typhoon fan on the left from my fan/radiator round 6 based testing here.  It was tested at roughly the same distance so I thought it would give some sense of scale to the charts.

Laing DDC-1 + XSPC top

This is the old model DDC-1 pump rated at 10 w and manufactured in 2003.

I think noise level is subjectively higher than average due to a buzz type noise present, but the pump is fairly consistent with very little issue with harmonic spikes even without decoupling.  Fully decoupled at 12V it measures roughly the same noise level as a GT-15 at around 1400RPM.  Noise scales well with voltage and at lower volts is approaching the 940RPM fan mark.  A good performer for it’s age, but not quite as silent as the newer models.

Koolance PMP-400 (DDC3.25) + Koolance COV-RP400 Top

This is the latest PMP-400 pump (18 watt) flavor with a nice thick/heavy acetal constructed top from Koolance.  Being acetal and extra thick, this top will likely provide some improvement to the thin and hard factory top material.

The pump/top combo does very well when completely decoupled.  Even at the extremely strong 12+V mark it’s just a hair more noise than a GT15 at around 1,000 RPM, that’s excellent!  You should however noticed there are two harmonic bumps that may or may not be associated with the simulated test rig.  The metal contact test however was all over the place with harmonics causing increased noise over the decoupled test from 3 dbA to  15 dbA.  This pump & top combo really likes to be decoupled completely if possible, the trick is likely some sort of lift or UN bracket system that will allow cooling and vibration decoupling.

Swiftech MCP-35X

This is the new PWM “Smart Pump” by Swiftech.  One obvious difference is the much larger operating range over voltage control of similar non PWM pumps.

Results are also similarly good when fully decoupled as the Koolance PMP-400 with some slightly higher numbers in some areas by 1-2 dbA.  It does have an extended range and the PWM feature could potentially be scaled dynamically, so those are all details to consider as well.  Overall a good showing that also like to be decoupled for best noise results.  Solid mounting can result in anywhere from 1 to 10 dbA more noise than a really well decoupled installation.  Of course being a DDC series high performance pump, you also may want to consider lifting the pump off the base to provide cooling and decoupling

Koolance PMP-450 (D5 Vario) + COV-RP450 Top

Well how does our larger vario pump model with factory speed controller work, these have generally been popular by the noiseless priority folks as they are factory built with a manual speed controller.  This first test is with the Koolance COV-RP450 top which is somewhat unique in that it includes an aluminum casing for the pump motor.  This serves to mount the pumps, but also to clean up the visual.  In addition, I suspect this help mask motor noises as well…  Let’s take a look:

Decoupled the Koolance PMP-450 with Koolance COV-RP450 top is the top performer, only hitting around 33 dbA at full speed, very good! However, similar to the other pumps when not decoupled, the noise levels climb significantly as RPMs increase creating up to 13dbA more noise than the fully decoupled test.

Koolance PMP-450 (D5 Vario) Sample #2 Stock Top

This is a second sample pump I had hand and initially decided to test it simply because I still had the factory top on it.  My intent was to compare stock top vs aftermarket top, but it turns out I also found some significant sample variance over the first sample.  This pumps had some rather pronounced spikes in noise level in a few places.

Overall this pump sample did good at middle speeds, but had higher than average noise levels at slow and high which I suspect is an impeller that’s slightly out of balance.  Sample variance is obviously a big factor in results so far and is going to make solid conclusions difficult with the low sample quantity being tested.

Koolance PMP-450S (D5 Strong)

The new king of power on the test bench…running with the factory top which it seems to like the best.

The Koolance PMP-450S strong did well, particularly under 14 V with the exception of a blip at 3800 RPM. Very good pump for noise and power.

Laing DDC 3.2

I’ve had this pump for a while, these are the last generation Laing DDC 3.2 series which is being replaced by the DDC 3.25 model.  This one also has the base “Feet” and a solid blue impeller.

This pump did very well and similar to the Koolance DDC 3.25 and only measuring about 1 dbA (less than perceivable noise difference) at full speed.  The thicker Koolance acetal top again seems to help reduce noise levels of the DDC series pumps.  It keeps noise at similar levels to an extremely silent GT fan at 1000RPM which is very good when decoupled.  Loosing the foam decoupler however reveals a similar erratic and harmonic variable results up to 9 dbA higher than the decoupled test.   I’m starting to sound like a broken record here, but decoupling is everything when it comes to pump noise reduction.

Summary Comparison Charts

Noise vs. Low Restriction Loop Flow Rate

First, lets look at the “Best Case” scenario where the pump is completely floating freely on a thick piece of foam.  Note, DDC series pumps should have a stand to allow base heat dissipation.

At the 2.3 GPM mark there are many pumps within about a 2dbA (not perceptible) grouping.  The Koolance PMP-450 with COV-RP450 top having a very slight (and perhaps testing error) edge in the charts.  The Koolance PMP-400 + COV-RP400, Swiftech MCP-35X, and Koolance PMP-450S are all similarly good here as well.  The PMP-450 sample 2 for some reason (suspect sample variance/impeller balance), was slightly higher.  The DDC-1 was also a bit more noisy.

All of the pumps were of good noise level though, and generally when decoupled were producing under the GT-15 noise level at around 1500 RPM.  If you had 10 each 40 dbA fans running in the background that total is 50 dbA, so it doesn’t take a whole bunch of fan noise to quickly mask pump noise “WHEN” the pump is properly decoupled.

So…what happens when you have a worst case mount, direct metal to pump contact….

All bets are off….There is really no consistency other than the general lack of consistency and general rise in noise level.  There are some things to learn here though, the bumps and dips are scattered throughout which means the vibration frequency and speed can be potentially “Tuned” to hit a low point.  If you have a solid mounted or less than desirable pump mount that is causing noise problems, you should seriously consider turning it down/up to see if you can find a low point in the noise curve.  Each case and each installation will likely have a unique harmonic noise/rpm profile/pattern, you just need to find the right pump speed to fall on the dips or low points.

CONCLUSIONS

  • Pump decoupling has HUGE benefits, up to 15 dbA lower noise levels than pumps without decoupling.
  • Pumps without decoupling are erratic in noise with massive peaks and valleys in noise level throughout the RPM range.
  • Thick Acetal pump tops may provide some benefit to reduction in noise levels over thin factory pump tops.
  • Pump sample variance does also affect noise levels, this may be due to how balanced the impeller is. Luck of the draw.
  • PWM pumps such as the Swiftech MCP-35X provide much more control and RPM range than voltage control.  They also provide the ability to dynamically increase decrease pump speed on thermal needs.
  • In general, all of these pumps are extremely silent pumps when decoupled.  Most general users with fans over 1000 RPM would typically have a hard time hearing these pumps at all in a normal fan noise masking environment.  Critical noise folks using ultra slow speed fans should put extra emphasis into pump decoupling methods and undervolting or reducing pump speeds.

Bottom line, if you want an extremely quiet pump, work on completely decoupling it from your case and consider tuning speed to seek the low points along the noise profile.  I would also highly recommend using pumps with PWM or fan controllers with thermal throttling capabilities to dial these pumps up and down with load.  Dynamic pump speed reduction setups allow for both ultra silence AND peak power when needed.

Cheers!

Martin