— Stren 8/9/2013
The Laing D5 is a popular pump. So popular in fact that you can buy just the basic vario model as the Alphacool VPP655, the AquaComputer D5, the Koolance PMP-450, the Swiftech MCP655 and the XSPC D5 Vario. Yes every water cooling company seems to rebrand the D5 and there are many varieties to consider. You can buy the vario with and without the default Laing top, or you can even buy the Laing top but with the ports threaded for regular fittings. You can also buy a different variant of the pump itself like the D5 Strong (24V capable higher speed version), or the PWM version, or the USB version or even the basic fixed speed version. Here is one such D5 with the standard Laing top:
So there are lots of options out there even if you have decided to go with the D5 family as your pump choice. This particular review doesn’t focus on the pump itself which we’ll cover in a separate review but instead focuses on the options for the pump tops for a single D5 pump. Each top will be tested for performance with the D5 Vario and the D5 Strong.
Why do pump tops exist?
The original Laing D5 comes with built in barbs for 1/2″ tube. Not every water cooler likes to use 1/2″ tube because it’s so large which makes it less flexible. However this has now been partially solved with the availability of Laing tops threaded for G 1/4 fittings. In addition the Laing top is not optimized for water cooling where flow is usually optimal around 1-1.5gpm. It’s also quite an ugly looking pump and water cooling for many has become about the aesthetic more than necessarily the performance or noise benefits.
In this roundup I’ll be looking at the following tops:
Alphacool HF D5 Pump Top Plexi
AquaComputer D5 Pump Top
EK D5 X-Top Rev2 (No longer available)
EK D5 X-Top CSQ White Acetal (Rev 3, the latest)
Koolance COV-RP450 Pump Top
NEW: XSPC D5 Top
Alphacool HF D5 Top
The Alphacool HF D5 top comes in both plexi and acetal versions. It’s also the most affordable top out there at $31 for the plexi version. Despite that price it comes in a nice box:
It also comes with two copper stop fittings for the alternative input and output ports:
However the screws that bolt the clamp to the mainbody do not match the usual alphacool copper theme. There is a mounting bracket but nothing to help isolate any pump vibration from the PC case itself.
The plexi top itself looks good when mounted to the floor of a case, however if it were to be mounted vertically the logo would be upside down and presumably hidden behind the pump inlet feed. Through the plexi you can clearly see the 90 degree bends that occur between the primary input/outputs and the secondary less efficient input/output:
The volute looks like the standard cone shape used by most high flow tops:
To test pumps I use a flow meter and a differential manometer and vary restriction by adjusting a brass gate valve. I adjust the gate valve to give different flow points and measure the pressure “gain” across the pump using the differential manometer. To understand how to read these plots check out this guide.
Leaks
Before getting stuck into the data it’s worth mentioning the issues that I had with this particular top. The first test I ran with a D5 Vario and after tightening the screws “tight enough” for my liking I found that the pump was leaking slowly and bypassing the o-ring seal. I proceeded to tighten the screws further (really really tight) which did finally seal the block. However one of the bolt heads started to strip. When I fitted the D5 strong for testing the same thing happened but this time the bolt head stripped completely and I had to drill it out. I wondered why the leaking would occur when the design was so incredibly similar to the EK top (the internals and bolt/clamp pattern seem identical). As far as I can tell the difference is the o-ring. The EK had a thicker o-ring. The EK part was also made of acetal which might also help. For now I can’t recommend the Alphacool because of this leak.
Performance Data
The Alphacool top does at least perform well. Through the region of interest (0.75gpm-1.5gpm) there is a small gain in performance over the standard Laing top regardless of whether you use the optimal ports or the alternative ports. If the top is compared to other tops with a D5 at max we can see that it performs at the top of the pack:
Summary
A well priced high performing high flow top that sadly can’t be recommended as it is let down by a tendency to leak unless you over-torque the clamp bolts.
Where to buy: PPCs
AquaComputer D5 Top
AquaComputer have two different D5 tops. Both of these can be used as standalone tops or mated directly to a compatible “Aqualis” Reservoir. The two versions are differentiated by the presence of a “fill level sensor”. This fill level sensor measures the water pressure at the bottom of a compatible Aqualis reservoir. The more water is in the reservoir the higher the pressure. The fill level sensor itself uses the same design as the MPS400 flow sensor that was reviewed here. The sensor still measures a differential pressure and so one end of the sensor is connected to the ambient air pressure. The fill level sensor functionality will be covered in a separate review. The top comes in the usual pretty AquaComputer packaging:
Accessories including a mounting bracket, stop fittings and a cable to hook up to the fill level sensor.
The top has two inputs and two outputs, only the front ports are labelled, but the top ports are simply in line with the front ports:
The stainless steel section on the right side of the top is the differential pressure sensor implanted into the side of the top. The third smaller hole on the top side is the sense point for the pressure sensor that acts as a fill level measuring sensor.
The volute is a fairly complex design and it can be seen that the outlet port is not directly inline with the output of the pump itself. The front port instead is doglegged and two 90 degree bends seem somewhat unnecessary:
This does not appear to be due to a lack of space because the design is already much bulkier than the competition.
There are four mounting points for the bracket which is an upgrade from the usual two. The bends in the stainless steel mounting bracket should also help to isolate vibration a little.
To test pumps I use a flow meter and a differential manometer and vary restriction by adjusting a brass gate valve. I adjust the gate valve to give different flow points and measure the pressure “gain” across the pump using the differential manometer. To understand how to read these plots check out this guide.
Performance with a D5 Vario:
The AquaComputer top performs poorly across the entire range of operation as it does not improve above the Laing top performance at all. The choice of port makes a small difference, neither option is particularly exciting.
Performance with a D5 Strong:
Overall we can see that the top does not perform as expected. Comparing it to the other tops in the roundup it can be seen that this does not just perform poorly, but it performs noticeably worse than any of the competition:
Summary
An expensive, poor performing, attractively chunky top with a cool but debatably useless water level sensing feature. This is the most expensive top in the roundup, even if you remove the fill level sensor option. At $50 I’d hope it was at the top of the pack in terms of performance, but instead it’s at the bottom.
Where to buy: FrozenCPU (only stocks the one without the fill level sensor), AquaComputer
EK X-Top D5 Rev 2
This is an older design that is no longer in production. As I already owned it I thought I’d throw it into the mix to see whether the Rev 3 top really adds anything.
No unboxing photos here as the box is long gone, but it came with the usual EK accessories, mounting plate, screws, stop fitting, allen key and instructions.
The clamp uses the same 8 bolts that the new Rev 3 uses. In fact the clamp holes line up perfectly with the new:
Because of this and the volute design looking identical it would be expected that performance would be identical.
To test pumps I use a flow meter and a differential manometer and vary restriction by adjusting a brass gate valve. I adjust the gate valve to give different flow points and measure the pressure “gain” across the pump using the differential manometer. To understand how to read these plots check out this guide.
Performance with a D5 Vario:
Performance with a D5 Strong:
As can be seen the top improves on the default Laing top across the range of interest. If we compare to other tops then we see that the top performs very well and almost identically to the later revision of the top:
D5 Vario:
D5 Strong:
Summary:
A strong performing top, although you can’t buy it anymore there is no reason to upgrade if you already have one!
EK X-Top D5 CSQ (Rev 3)
This is the latest version of the EK single D5 top. It is very much a visual refresh of the old Rev 2 top to conform with the CSQ theme. Recently EK also launched the plain non-CSQ version. The box also conforms with the CSQ style and is bright pink which I believes signifies something pump related in the EK lineup:
The top is well packaged and seperates the top from everything else:
The accessories include a stop fitting, a mounting plate but nothing that might help reduce vibration being transferred to the case:
The clamp is made of matching acetal and will line up with the top:
The logo is orientated like the Alphacool, i.e. correctly if the pump was to be mounted to the bottom of a case, but not if the pump was mounted vertically to the side. In this case it would be back to front and hidden behind some tubing most likely.
To test pumps I use a flow meter and a differential manometer and vary restriction by adjusting a brass gate valve. I adjust the gate valve to give different flow points and measure the pressure “gain” across the pump using the differential manometer. To understand how to read these plots check out this guide.
Performance with a D5 Vario:
Performance with a D5 Strong:
The top therefore does a good bit better than stock regardless of the output used. If we compare to other tops we see that EK is at or very near the top:
D5 Strong:
Summary – Gold Award – At $38 this top provides excellent value for money. It’s one of the top performers and you can offset some of the cost by buying the cheaper topless “bare” edition pump instead of the full model. My only minor complaints are that there is nothing supplied to dampen any vibration/resonance when this is mounted to the case. Also unlike the more expensive Koolance top it doesn’t cover any labels on the pump itself.
Where to buy: PPCs
Koolance COV-RP450 D5 Pump Top
The Koolance D5 top is a multi purpose top because it combines not just a top, but optionally a reservoir base. Packaging is standard Koolance black:
The top comes with mounting brackets (2 piece not 1 which will be a bit more fiddly), a stop fitting and the necessary adapter to mount a 60mm Koolance reservoir to the top:
At $45 it’s a few bucks more than the EK top, however it comes with a cover to hide your D5 completely. No longer a need to remove ugly stickers. The downside of course is that any speed control will be harder to get to:
The actual clamp bracket is metal and because it’s thick only 4 screws are needed to secure it. It sticks out the rear of the top and the two mounting brackets can be attached directly to the metal plate:
The screws however could have been countersunk which would have given a cleaner look:
To test pumps I use a flow meter and a differential manometer and vary restriction by adjusting a brass gate valve. I adjust the gate valve to give different flow points and measure the pressure “gain” across the pump using the differential manometer. To understand how to read these plots check out this guide.
D5 Vario Performance:
D5 Strong Performance:
The top performs very well regardless of the ports used. If we compare to other tops we see that it is near the top:
Summary – Gold Award A fairly priced high performance top that covers the pump body completely. The option to add a reservoir is nice and a 120mm reservoir can be added for only $24 extra which is pretty affordable. My only niggle is that Koolance could have done more with the pump mount to try and isolate vibration.
Where to buy: PPCs
D5 Single Top Summary
It was very noticeable and unsurprising that Alphacool, EK and Koolance had similar high end performance, beating the default Laing top across flow rates of interest to water coolers. It was however surprising that AquaComputer’s top was so far behind. However differences that look large on a pump plot may be small in reality. If the expected flow in a “medium” restriction loop is plotted it can be seen that the actual differences may be small enough to choose on secondary issues if you’re not a “min-maxer”:
Given that “bare” pumps are now sold for less than the original D5 that comes with the Laing top then the case for buying an after market top is stronger. Of the 5 brands, I would recommend both the Koolance and EK. They are fairly priced and perform at the top of the bunch and didn’t have any of the leak issues I had with the Alphacool.
Gold Awards:
EK X-TOP CSQ:
Koolance COV-RP450:
