by Sergey Lepilov
11/30/2007 | 11:02 AM
A high-performance liquid cooling system for the PC cannot be cheap. That’s an axiom (in case you’ve forgotten your school classes, an axiom is a proposition that does not need proving). This point can be argued long and hard, but the person who’s trying to prove the opposite usually runs out of his arguments as soon as he has to face the problem of choosing, ordering, purchasing or assembling a liquid cooling system by himself. Of course, putting forth that axiom I do not count in liquid cooling system assembled out of radiators from old cars or even trucks, hand-made water-blocks and other components. In this case, every such system will have a different cost. So, if you are seriously going to enter the not-yet-wide circle of owners of liquid cooling systems, you must be prepared for a considerable financial investment, about five times the price of the most efficient and expensive air cooler.
You must be aware that the frequency growth of the overclocked CPU (or any other computer component) with a liquid cooling system will not be proportional to the price difference between liquid and air cooling. Then, you may wonder if it wouldn’t be better to buy an off-the-shelf liquid cooling solution? If you do, you don’t have to spend your time searching and ordering individual components and don’t have to wait for them to be delivered and pay for the delivery. You don’t have to invent anything with respect to your system case when you are trying to install your liquid cooling system. An off-the-shelf system is also going to be cheaper than the one bought in parts.
Koolance offers a compromise answer to that question. Besides various water-blocks for all PC components and a lot of accessories, this company supplies several types of liquid cooling units that combine a radiator, fans, pump, expansion tank, and various monitoring and control tools. The user can choose water-blocks to his own taste and preferences. This seems like a good idea to me. And now I’ve got a chance to check out the performance of the most expensive liquid cooling system from Koolance. I’ve got the Koolance Exos-2 LX kit and a set of water-blocks for it.
I will staudy the components in this review and test their performance and noise characteristics. Let’s get started.
I want to start out with the biggest box that contains the Koolance Exos-2 LX, a relatively new model of a liquid cooling system. The thick cardboard is devoid of any design or pictures, showing only the model name and the name of the manufacturer. Thermalright, one of the current leaders of the air cooling industry, is just as ascetic when it comes to decorating the packages of its products. Inside the box there are two pieces of foam-plastic that fix the cooler by the sides:
On the piece of cardboard above there lie pipes, coolant, and a user manual. An individual pack contains the following accessories:
The two pipes included into the kit differ in length and diameter.
The pipe with an internal diameter of 10mm is about 1.5m long. The pipe with a diameter of 6mm is only 0.8m long.
The pipes are flexible, yet much stiffer than those of the Zalman Reserator XT, for example. This prevents the pipe from bending but it is harder to deal with such pipes inside the system case. A king of a problem too, the pipes have a noxious smell I had to put up with during my tests. That’s not a serious problem, though, as you can easily replace the pipes with those that suit your taste, smell and other feelings.
The user’s manual to the Koolance Exos-2 LX is a small brochure:
The blue coolant in a thick opaque pack was made in Korea and marked as Coolant LIQ-700BU.
Its volume is 700 milliliters. The coolant consists of 70% distilled water and 30% Carboxylate. It is recommended to replace the coolant in the system once each year. Now that we’ve examined the package and the accessories, it’s time to have a look at the main block of this liquid cooling system.
The beautiful and stylish device looks like an armored personnel carrier but with no wheels and gun.
The acrylic front panel, small monitoring display and control buttons together with the highlighting of the expansion tank give an irresistible appearance to the main block of the Koolance Exos-2 LX system.
This block measures 213x95x495mm at 4.1 kilos of weight. The housing is made from aluminum. Here is a photo of the top panel of the block:
You can see two wire grids of 120mm fans and the fans themselves underneath. To the right is an expansion tank with a translucent cover and a plug.
There is nothing exceptional on the bottom panel:
The large slits in the bottom of the block provide some fresh air for the radiator but the manufacturer says most of the air comes in through the side grids of the case. There are four feet on the bottom – you should glue the included rubber pads to them to make the block stand steady. I want to note that the feet with the pads are less than 8mm high – you’ll see shortly why I mention this fact.
There is a small digital indicator of the fan speed level (10 levels) and of the temperature as reported by one of the three sensors, and four small control buttons.
Below them is an acrylic panel with the cooler’s name and two chrome brackets that serve an aesthetic rather than functional purpose.
At the rear panel there are the input and output fittings, a connector for the interface cable (which does double duty as a power cable), and a small regulator of the pump performance:
The latter can even turn the pump off as the warning label informs you.
The two fans at the top of the housing are installed upside down for exhaust:
According to the labels, these fans run on ball bearings and have a peak consumption of about 3W. The fan speed can be regulated either automatically (depending on the temperature) or manually according to the 10-level scale:
Removing the bottom panel of the Koolance Exos-2 LX, I could take a look at its internal design:
The main block of the system accommodates a pump, reservoir, radiator, and control and monitoring elements.
The manufacturer doesn’t specify the performance of the pump, but it is quite noisy at its maximum and runs the coolant along the pipes at a speed that the Zalman Reserator TX, for example, may envy.
An indisputable advantage of serially made liquid cooling systems is that you don’t have to select, search for and purchase the components individually. The assembly and installation process is also very simple with off-the-shelf products and requires much less effort and time. The Koolance Exos-2 LX is not an exception in this respect. You can find the assembly and installation guide on the official website, I’ll just point out the key steps to you.
The pipes are cut up the necessary size and put into the system case through the bracket with the interface connector and the card that has connectors for two sensors and additional fans:
Three thermal sensors are already attached to that card – you should place them on the water-blocks. It also has one 2-pin power cable with a Molex connector. Then, you attach the pipes to the water-block(s) and to the Koolance Exos-2 LX and plug the interface cable into the main block.
The fittings included into the Koolance Exos-2 LX kit (and the fittings in the main block) are equipped with valves so that the liquid wouldn’t pour out on your connecting and disconnecting them. Note also that the bottom fitting is the output one, and the top fitting is the input one.
Now that the system forms a closed circuit and you have made sure the connections are secure, you can pour the coolant in. The manufacturer provided a small rubber funnel you can insert into the expansion tank.
It’s easy to handle the coolant in the pack – at least I didn’t let any drop fall past the opening of the tank. After I had filled and pumped the system up with one water-block on the CPU, I had about one third of the coolant left in the pack. Later on I had to add some 100-150 grams of coolant more when I included graphics card and chipset water-blocks into the circuit.
The placement of the Koolance Exos-2 LX relative the system case is most important. The user manual shows an example in which the main block is placed on top of the system case. I think it is not a good position. Well, it is indeed good in terms of compactness and style, but the liquid cooling system is going to keep the temperature higher than it could. The problem is that the system case is getting hotter when your PC runs applications, and the air that the cooler’s radiator will be receiving will be hotter than the ambient temperature. Moreover, if the system case stands in a special niche of your computer desk, there will be extra resistance to the air flow since the surface of the desk is a just a couple of centimeters higher than the grids of the Koolance’s fans.
To verify these theoretical speculations I checked out the cooler’s efficiency in two positions: when the Koolance Exos-2 LX was standing on the system case and when the cooler was placed next to it. And the latter variant proved to be 5°C better in terms of temperature under load. The Koolance Exos-2 LX was tested with the CPU water-block in this test and I guess the temperature gain would be even higher if there were two more water-blocks in the circuit.
That is the reason why I placed the Koolance Exos-2 LX next to the system case for my tests.
I could also win a couple of degrees by lifting the Exos-2 LX up above the surface the system’s feet stand on:
I had to use baby food jars for that purpose – not quite aesthetic but good for a temporary test. It seems that the air flow that comes to the radiator through the slits in the cooler’s bottom panel is no less important than the air that comes in through the side panels. The difference in temperature isn’t critical, of course, but you know how to improve the efficiency of the discussed cooler to its maximum now.
Filled up and turned on, the Koolance Exos-2 LX shows blue highlighting of the expansion tank and control panel:
The rather uninformative monitoring display shows the temperature of one of the sensors. You can use the buttons to select the units of temperature, the speed of the fans (according to the 10-level scale), and the threshold temperature for each sensor on surpassing which the system automatically switches to its full performance.
The Koolance Exos-2 LX comes at a recommended price of $375.
That’s about all I can tell you about the main block of this liquid cooling system. Its performance, noise and other characteristics will be discussed below in the appropriate section. The next sections will cover Koolance’s water-blocks none of which is included into the standard Exos-2 LX kit.
The CPU water-block Koolance CPU-330 is shipped in a small tight-fitting cardboard box.
The text on the box tells you the name of the manufacturer, the water-block model, the supported platforms, and the country of origin. Besides that, there is a small sticker on the side that lists Koolance fittings compatible with this water-block. Koolance puts such a sticker on every water-block, which is very convenient for the user. You won’t make a mistake when choosing your components even if you are new to the whole liquid cooling business.
Besides the water-block, the box contains the following accessories:
The original installation manual was missing in the box, but I found there two sheets with text from the electronic manual.
The base and interior of the CPU-330 water-block are made from high-purity copper. The base is also coated with 21-carat gold. The cap of the water-block is made from anodized aluminum.
The water-block measures 60x60x18mm at 198 grams of weight. The Koolance CPU-330 can be used with fittings of 6, 10 and 13mm in diameter.
Judging by the interior design you can have a look at through the holes, the water-block has pyramid-like ribbing inside. Besides that, there is a plastic guiding bar, shaped like a pack of staples, between the holes inside. It must be meant to optimize the liquid flow inside the water-block.
The Koolance CPU-330 is only 18mm thick, and the fastening plate is secured on the rib that goes along the top of the cap.
The water-block’s base is protected from scratches with polyethylene piece (don’t forget to remove it before installing the water-block on your CPU). The film protects the flat and immaculately polished surface:
The water-block supports mainboards with Socket 478, LGA775, Socket AM2, Socket 754/939/940 and even with the hopelessly obsolete Socket A (462). It is always fastened by means of a steel clip, a back-plate with a rubber pad and threaded pins, and spring-loaded figure nuts:
Despite the rather large fastening plate and the low height of the water-block, there were no elements on the mainboard that would get in the way. The water-block is pressed hard to the CPU but I think you don’t have to tighten the nuts to the end. It is recommended to glue a thermal sensor to the base of the water-block before the installation in such a way that it wouldn’t be in the spot of contact between the CPU heat-spreader and the water-block base. So, I would suggest that you first apply some thermal grease and see what trace it leaves on the heats-spreader and then glue the sensor near the trace.
The recommended price of the Koolance CPU-330 is $50.
The Koolance CHC-120 is a water-block for a mainboard’s chipset. It is packed into a small box that resembles the package of the CPU water-block.
This box contains the following things:
The water-block looks very much alike to the above-discussed CPU-330:
It has a round shape and a copper sole coated with 24-carat gold, too. And it’s got the same cap from anodized aluminum. There is a small groove for the wire fasteners going along the center of the cap.
The internal design of this water-block is different from the CPU-330:
The pins that rise from the water-block’s base are rectangular rather than pyramidal, and there are no plastic inserts inside the water-block.
The Koolance CHC-120 measures 3.9x3.9x3.3mm.
It is small even in contrast with the CPU-330. The official website says the water-block weighs 249 grams, but I guess it’s a mistake since the CPU water-block is only 198 grams.
The sole is covered with protective film:
The surface is finished just like on the CPU water-block:
The water-block is designed for fittings with an internal diameter of 10 or 6 millimeters. Installing it on the mainboard’s chipset is elementary. You can find a handy compatibility list on the official website. It shows what mainboards and graphics cards (meaning the length of the graphics card) the water-block is compatible with.
The following picture shows how to install the Koolance CHC-120 on the mainboard:
Besides using screws, the water-block can also be installed on the mainboard by means of wire brackets.
This water-block is priced at $35.
I guess the most exciting and useful water-block in this review is the Koolance VID-282, which is meant for cooling Nvidia’s GeForce 8800 GTX and Ultra graphics cards. The small flat box feels surprisingly heavy for its dimensions. The water-block’s model is specified on the face side of the box. Supported fittings and adapters are also listed here.
This box contains a polyurethane tray with the water-block and its accessories.
There’s not much interesting among the accessories, though:
Two types of thermal pads, a pack of Stars thermal grease, screws with plastic spacers, and an installation manual – that’s all you will find included into the Koolance VID-282 kit.
The water-block is cute indeed:
Its base and multi-channel interior are made from copper coated with 21-carat gold. The top cap with the Koolance logo is steel. Everything is polished off to a mirror shine.
The water-block measures 185x120x14mm and is heavier than most super-coolers even without coolant – 907 grams!
There are two caps on the face side of the top part of the water-block. They are meant for organizing liquid cooling of two GeForce 8800 GTX/Ultra graphics cards in a SLI configuration.
You have to use special connecting bushings and adapters, purchased separately, for that. Fittings with an internal diameter of 6, 10 or 13mm are inserted into the openings on the other side.
It is simple to install the water-block on a graphics card. The step-by-step procedure is described and illustrated in the manual. First you should glue thermal pads to the spots of contact between the water-block and the graphics card (excepting the GPU):
Two types of thermal pads of different thickness and color are included into the kit. I used the thinnest pads for my tests. As the photo shows, the water-block has contact not only with the GPU but also with the graphics card’s memory chips, power circuit elements, and NVIO chip. In other words, no part of the GeForce 8800 GTX/Ultra will be left uncooled. :)
The water-block is secured on the graphics card’s PCB with screws and plastic spacers. Three screws proved not enough and I had to use screws from the GeForce 8800 GTX’s stock cooler additionally.
Of course, the high-end graphics card with a cooler weighing almost 1 kilo looks alarming, so you may want to secure its top right corner additionally inside the system case.
That’s the graphics card with the installed water-block inside my system case:
The Koolance VID-282 comes at a recommended price of $93. Koolance also offers the VID-290 water-block for the AMD Radeon HD 2900 series at the same price.
The last of the water-blocks to be discussed in this review is the Koolance HD-55-L06. It is meant to cool 3.5” hard disk drives. The water-block comes in a small box designed like the previous boxes.
Besides the water-block, the box contains a brief installation guide and a pack with screws, nuts and spacers:
The water-block is almost the same size as a regular HDD: 102x164x15mm.
It is made from aluminum and weighs 105 grams. It has a simple design. There is a metallic surface of the heat-spreading plate on one side and a robust insulating pack with the coolant on the other side:
The black plate can be removed so that the water-block could cool two HDDs simultaneously.
The internal diameter of the fittings is 6 millimeters. The installation procedure is described in the manual you can find at the official website. The recommended price of this water-block is $50.
Koolance offers a wide range of accessories to its liquid cooling systems. Besides fittings, adapters, connectors and other trifles, there are even splitters of water flow from one into four channels:
I want to note the highest manufacturing quality of each component. All the threaded connections are equipped with rubber spacers and are perfectly fitted together. You don’t have to use any tools – everything is joined and fastened with your own hands.
The testbed and methods haven’t changed much since our Zalman Reserator XT review. So, the Koolance Exos-2 LX and its opponents were tested in a closed system case with the following configuration:
The quad-core CPU was overclocked to the maximum stable frequency it had with the air cooler. That was 3483MHz. The core voltage was set at 1.6625V in the mainboard’s BIOS.
CPU-Z, SpeedFan and Everest reported a core voltage of 1.59V at that. The memory voltage was increased to 2.1V. The other mainboard voltages were left at their defaults.
All tests are performed in Windows XP Professional Edition Service Pack 2. SpeedFan 4.33 is used to monitor the temperature of the CPU, reading it from the CPU sensor.
The CPU is heated up by means of OverClock Checking Tool version 1.1.1b in a 24-minute test during which the system remains idle in the first and last 4 minutes for the temperature to stabilize.
The CPU temperature didn’t improve with any of the tested coolers if the duration of the test was 60 rather than 20 minutes. The liquid cooling system would achieve its peak after 9-12 minutes under OCCT.
I perform at least two cycles of tests and wait for 20 minutes for the temperature to stabilize during each test cycle. The maximum temperature of the hottest CPU core in the two test cycles is considered as the final result (if the difference is not bigger than 1°C – otherwise the test is performed once again). Despite the stabilization period, the result of the second cycle is usually 0.5-1°C higher with the air cooler. The results of both tests were identical with the liquid cooling system.
The mainboard’s automatic fan speed management (Q-Fan technology) is disabled for the time of the tests. The thermal throttling of the Intel Core 2 Quad processor is controlled with RightMark CPU Clock Utility version 2.30. Our CPU begins to skip clock cycles on reaching a temperature of 82°C and higher.
The ambient temperature was monitored by means of an electric thermometer and remained at 23.5-24°C during the tests (marked with a red line in the diagrams). The fan rotation speeds are shown in the diagrams as reported by SpeedFan.
The noise level of each cooler was measured according to our traditional method. The subjectively comfortable level of 36dBA is marked with a dash line in the diagram; the ambient noise from the system case, without the CPU cooler, was about 34dBA when measured from a distance of 1 meter.
The Sysconn GeForce 7900 GS graphics card had been used in our tests before. I also added the GeForce 8800 GTX from XFX into this review to check out the efficiency of the graphics card water-block. Here are a couple of photos of the card:
As you can see, the card is equipped with the reference cooler based on two copper pipes. I could overclock the card to 621MHz GPU and 2030MHz memory with its stock cooler.
The Zalman Reserator XT had been compared with the Thermalright Ultra-120 eXtreme cooler with two high-performance Scythe Minebea fans (4710KL-04W-B29) at 1140rpm for intake and exhaust. This air cooler is going to be the opponent to the Koolance Exos-2 LX in this test, too. The results of the Reserator XT will also be listed for comparison. Besides testing the Exos-2 LX with the CPU-330 water-block I also tested it with the Zalman ZM-WB5 water-block. I used pipes with an internal diameter of 10mm.
My today’s test program opens non-traditionally with a noise level test. I want to show its results first so that you can see what operating mode of the Koolance Exos-2 LX system is the most practical, i.e. comfortable for constant use. In this test the fan speed was being changed manually along the 10 available grades and the noise level was measured from a distance of 1 meter. The pump was turned off during the test. Here are the results:
As you can see, the third and fourth speeds of the two 120mm fans are subjectively comfortable – the difference between the two speeds is negligible in decibels. The further increase of the fan speed leads to a considerable growth of noise. At speeds higher than the sixth one it is quite uncomfortable to be near the operating Exos-2 LX for a long time. As for the maximum speed, you may only want to use it for benchmarking and setting new records. The noise produced by the pump is also shown in the diagram, but the pump isn’t noisy even at its max performance although audible when the fans of the Exos-2 LX are working at the fourth or fifth speed.
The next diagram shows the temperature of the overclocked quad-core CPU (the liquid cooling system has only one water-block in the circuit – for the CPU).
I should first note the low efficiency of the CPU-330 water-block. The Zalman ZM-WB5 keeps the temperature as many as 8°C lower than the CPU-330 in the quiet mode. Frankly speaking, I had expected the water-block from Koolance to prove more efficient than Zalman’s, but it’s just the opposite in reality. The gap between the water-block diminished when I increased the pump performance and the fan speed, yet the Zalman ZM-WB5 was ahead anyway.
Comparing the two liquid cooling systems with the same water-block (Zalman ZM-WB5), the Koolance Exos-2 LX cools the CPU better by 2°C in the quiet mode. The gap grows to 8°C at the max performance, but the Exos-2 LX is considerably noisier than the Zalman Reserator XT (53.3dBA against 43.8dBA). Note that it is the increase of the fan speed, not of the pump performance, that contributes the most to the reduction of the CPU temperature. Moreover, if the two fans of the Exos-2 LX system are set at 1080rpm and the pump performance is changed from comfortable to maximum noise, the CPU temperature doesn’t change under load and even rises up by 3°C in idle mode. Running a little ahead, I can tell you that the efficiency of the liquid cooling system depends more on the pump performance if the hydrodynamic resistance is increased, which is quite logical.
The maximum stable frequency of the CPU when cooled by the Exos-2 LX in the quiet mode with the Zalman ZM-WB5 water-block was 3610MHz at a peak temperature of 67°C and a voltage of 1.6125V. I performed this test the last of all when the mainboard’s BIOS had been updated to version 0601, the CPU Voltage Reference was set at 0.63x and the CPU Voltage Damper was set at Enabled. As a result, the CPU was stable at a lower voltage, but a higher temperature (by 3°C). When I selected the highest fan speed, the CPU was stable at 3708MHz and had a peak temperature of 61°C, which is the absolute record for this CPU in our tests. Unfortunately, the Exos-2 LX is too loud in that mode.
Then I added the chipset water-block into the circuit. I had to remove the heatsinks with heat pipes from the mainboard and install copper heatsinks onto the power elements. The ASUS P5K Deluxe cannot monitor the chipset temperature, so I measured it using a thermal sensor included into the Exos-2 LX kit. I first attached it to the base of the standard copper heatsink that was installed on the mainboard originally and then I glued it to the base of the CHC-120 water-block. The chipset proved to be 60°C hot with its standard passive heatsink but only 39°C hot with the water-block (there can be a minor inaccuracy about the numbers). I guess that’s a superb result but it is only going to be practically valuable if you want to overclock the CPU by increasing the system bus frequency above 500MHz. I can also add that the CPU temperature grew by 2°C under peak load (the CPU was overclocked to 3610MHz at 1.6125V in this and subsequent tests) when I had included the chipset water-block into the circuit.
Next I added the graphics card water-block into the circuit to work along with the CPU and chipset water-blocks. The VID-282 was cooling the overclocked GeForce 8800 GTX in this test. The diagram shows the temperatures of the graphics card’s GPU and PCB components.
The performance of the liquid cooling system is impressive in contrast with that of the GeForce 8800 GTX’s stock cooler. Such a hot graphics card proves to be no hotter than 60°C (GPU temperature) and 50°C (PCB temperature) with the liquid cooling solution from Koolance. Moreover, the thermal sensor of the Exos-2 LX system attached inside the closed system case reported a decrease from 50°C to 34°C in the air temperature when the graphics card’s cooler was replaced with the water-block and the system was running Unreal Tournament 3 for an hour. And to remind you, the blower of the GeForce 8800 GTX’s stock cooler exhausts the hot air out of the system case! I wonder what the difference would be in comparison with graphics cards whose coolers do not exhaust the air.
But while the graphics card temperature decreased dramatically on my adding the VID-282 water-block into the circuit, the temperature of the CPU grew up after that:
The Firefly Forest test from 3DMark06 doesn’t load the CPU fully (as you can see by the difference in the CPU temperature with and without the graphics card water-block). On the contrary, the CPU temperature grows suddenly in Unreal Tournament 3 even when the graphics card water-block is removed from the circuit and the GeForce 8800 GTX works with its stock cooler. You can only reduce all the temperatures by increasing the fan speed and the performance of the pump.
The only water-block I did not test was the Koolance HD-55-L06. The temperature of the Samsung HD501LJ hard disk drive installed in our testbed is not higher than 39°C even during long write/seek operations, so there is no sense in installing a water-block on such a cool HDD. Liquid cooling may come in handy for Western Digital’s Raptor drives, but I didn’t have to such HDDs at my disposal.
First of all I’d like to point at the main, and perhaps the single, serious drawback of the Koolance products I have tested. The CPU water-block is too weak. At a recommended price of $50, the Koolance CPU-330 is inferior to the cheaper Zalman ZM-WB5 ($35) in the comfortable operation mode. On the other hand, you can just buy a different water-block because the CPU-330 is not included into the standard Koolance Exos-2 LX kit and you won’t pay for it if you don’t want it.
As for the Koolance Exos-2 LX system and the other components, they deserve a lot of praise from me. Featuring high performance, simple assembly and installation procedure, monitoring by three sensors, regulated fan speed and pump performance and stylish appearance, the liquid cooling kit from Koolance is sure to attract people who are into such cooling solutions. I was especially impressed at the VID-282 water-block for graphics cards as I had never seen such an effective and quiet cooling solution for cards like GeForce 8800 GTX/Ultra or Radeon HD 2900 XT. The price of the Exos-2 LX, even though high, is quite competitive on the market of serially made liquid cooling kits. Of course, you can try to assemble something like that by yourself, but I doubt that a hand-made solution will be cheaper or smaller or prettier.