by Sergey Lepilov
05/12/2008 | 05:39 PM
The idea of placing compact liquid-cooling systems for CPUs inside the system case is not that new. Various manufacturers keep releasing new solutions like that and improving the existing ones. The reasons behind that are absolutely natural, because the words “liquid-cooling” are still pretty intriguing for commencing overclockers as well as for some mainstream users. And if systems like that are also being offered at quite democratic prices, then it is very hard to fight the temptation of purchasing something like that.
<%BANNER[article]%>However, there is one problem here. The thing is that although this is liquid-cooling we are talking about, systems like that are often less efficient and much noisier than high-quality air coolers. So, keeping this fact in mind, it hardly makes much sense t go for system like that. Today, however, we are going to check things out ourselves. We will talk about two compact liquid-cooling systems from AURAS and XIGMATEK companies and introduce to you a very original and innovative cooler from Akasa. So, let’s get started, and let’s first talk about the exciting new product called Akasa Revo.
The first participant of our today’s test session is presented by Akasa Company. I doubt that overclocking fans know much about it and a variety of inexpensive aluminum heatsinks and simple fans that they make. We are going to make up for this omission and discuss their innovative cooling solution.
The cooler ships in a small cardboard box with almost a full-size cooler image on the front and a detailed description of its features and technical specifications on the back:
Besides the actual cooler, the box also contains two plastic retention brackets, and installation guide and a tube of Akasa thermal compound:
Once you have Akasa Revo in your hands, you will undoubtedly be surprised how little it weighs: only 300g! Of course, since the whole thing is made only of aluminum, even the cooler base has not a gram of copper in it:
The cooler design is more than original. There is a “plump” aluminum heat-spreader in the base with two pipes connecting it to the radiator:
The radiator is cooled with a 92-mm fan sitting in a plastic frame:
The frame and the fan can be easily removed letting us take a close look at the Akasa Revo design:
This cooling system works according to a very simple principle. The scheme below gives you a better idea of what it is:
So, the CPU heats up the liquid-coolant inside the circuit. Warm coolant then travels up to the fine-finned radiator with about 1200sq.cm cooling surface. It goes through the radiator fins, which are cooled by the airflow from the fan. After that the coolant travels down, back to the heat-spreader. It literally goes down, because Akasa Revo can be most efficient only if installed as shown on the picture above. Nevertheless, the manual suggests that the cooler may also be installed in one more way, although the highest efficiency in this case is not guaranteed:
According to the manufacturer, the coolant travels at pretty high speed within the circuit thanks to a special additive that makes the liquid bubble when hot. Of course, the chemical contents of the coolant is not disclosed anywhere.
As I have already mentioned above, the radiator is cooled with a 92 x 92 x 25mm fan supporting PWM rotation speed control:
The fan rotation speed may vary from 600RPM to 2200RPM generating 17-26dBA of noise and creating 11.44~41.96CFM airflow. The fan ball bearing is claimed to serve you well for 45,000 hours.
The aluminum cooler base is very even with a pretty ok finished surface:
Frankly speaking, we cannot explain why the manufacturer decided to give up copper base for Akasa Revo cooler, as copper is known to conduct heat much better than aluminum, which could have improved the cooling efficiency quite noticeably.
The cooler can be installed onto Socket 754/939/940/AM2 and LGA 775 platforms very easily and doesn’t require the mainboard to be removed from the system case. You pick the proper retention bracket of the two bundled with the cooler and install it onto the processor socket. After that the cooler goes right on top of the CPU and is locked with two wire clips at the base:
The contact is very secure and the cooler base fits snugly into the square plastic bracket that is why it will under no circumstances move or rotate on the CPU heat-spreader. Inside the system case the cooler looks very compact and doesn’t get in the way of any other components:
Akasa Revo retails for $33.
The next cooling solution with a name that speaks for itself – “Conditioner” – was provided by AURAS, a frequent guest of our cooling solution reviews.
The new cooler is shipped in a box made of thick cardboard. There is a photo of the cooler on the front of the box. The sides of the box contain thermal charts and technical specs of the solution:
Inside the cardboard box there is a polyurethane foam casing that holds the cooler and accessories bundled with it. The accessories bundle includes a retention bracket for LSG 775 mainboards, a retention bracket for AMD K8 mainboards, power cable for the pump and fan, plastic locks, installation manual and a syringe with thick gray thermal compound:
AURAS Conditioner (GTO-990) is a dual-module cooling system that includes a water block combined with a pump and a radiator with a fan:
The system components are connected with one another with two non-transparent pipes 6-mm in internal diameter. Now let’s take a loser look at the cooler components.
The radiator design is pretty primitive. It consists of thin aluminum fins sitting on heatpipes filled with coolant. The radiator is 99 x 61 x 138mm big and weighs 555g:
There is a 92 x 92 x 25mm fan on top of it that supports PWM control of the fan rotation speed, which can vary from 80RPM to 2400RPM creating 47CFM airflow and generating 23dBA of noise. To lower the noise level, they placed the fan onto four silicone spindles that absorb the vibrations:
Besides, the fan also boasts blue highlighting.
The second part of the AURAS cooling system is a water block combined with a pump:
This simple device is very compact: it measures only 37 x 64 x 84mm. The pump capacity is not mentioned in Conditioner’s specifications, but its rotor rotation speed is claimed to be 1400RPM. The ceramic pump bearing should serve you well for 70,000 hours, and it can be powered from any of the available three-pin connectors of your mainboard or from a Molex connector of your PSU with a corresponding adapter. There is a blue LED in the upper transparent part of the pump.
The scheme below that we borrowed from the company’s official web-site gives you a great idea of the water block design peculiarities:
As you can see, the water block boasts very primitive architecture. Contemporary water blocks do not use this particular design any more (implemented in this particular way). As for the coolant they use, there is no info regarding it chemical contents or service time.
The water block base is covered with a protective film:
And it turned out there is really a lot to protect:
Ideally even and perfectly polished base doesn’t require any additional effort from you.
AURAS Conditioner can be installed using two types of retention brackets attached to the base with four screws:
The radiator and fan bloc is fastened to the case rear panel with plastic locks. This way the entire cooling system sits very compactly inside the case:
And the blue fan and pump highlighting add a nice touch to the way your system looks:
URAS Conditioner is priced around $55, which is not expensive at all for a liquid-cooling system these days.
The third and the last cooling solution we are going to talk about today is the one from XIGMATEK, which our regular readers should know very well by now.
XIGMATEK AIO-S80DP comes in a cardboard box that has a half-open front revealing the entire XIGMATEK AIO-S80DP cooler, so that you could check it out even without taking out of the box:
The reverse side of the package has very detailed technical specifications of the cooler and lists all of its unique features.
The cooler itself sits in snugly fit transparent plastic casing. Its accessories are hidden at the bottom of it:
Besides, there is also an installation guide in several languages:
The cooler is not very big. It measures 121 x 114 x 128mm and weighs 840g. XIGMATEK AIO-S80DP looks almost like a “cube” made of two aluminum radiators. There is a fan installed between them and a pump combined with a coolant tank and a water block at the bottom of the device:
The detailed technical specifications of this solution are given in the table below:
As you can see from this table, it is a compact and universal liquid-cooling system that fits into the system case and is installed right on top of the CPU.
The two radiators measure 80 x 88.7 x 22mm and are made of solid aluminum:
They boast pretty classical design: thin fins are soldered (or glued) to the radiator channels:
Between the radiators there is an 80-mm fan with PWM fan rotation speed controller. The whole thing is covered with aluminum casing indicating the airflow direction:
There you can also see the plug on one of the heatsink fill holes covered with a warranty sticker. The system comes fully filled and ready to use that is why you don’t have to add anything to it. Although some time down the road this option may come in handle, of course.
The water block base is made of copper:
The base surface gets a good B for finish quality:
It is impeccably even. Unfortunately, we can’t speculate about the actual internal design f the water block, however, we managed to find a schematic picture of the XIGMATEK AIO-S80DP cooler design:
As we can guess from the lower part picture, the water block features cylindrical structure with numerous thin copper rods inside.
There are two 12V power cables for the fan and the pump f the XIGMATEK AIO-S80DP cooler:
XIGMATEK AIO-S80DP can be installed on contemporary mainboards for Intel processors with two plastic retentions. They are fastened to the mainboard PCB with the included bushes and are tightened up to the backplate at the bottom of the board:
After that the cooler fits on top of the CPU and is fastened to the previously installed retentions with the bundled spring-screws:
The cooler is pressed very firmly against the processor heat-spreader. Despite the seeming bulkiness, XIGMATEK AIO-S80DP fit onto our mainboard without any problems. Now we should just connect the power cables to the board (or to the PSU using the proper adapters) and the system will be ready to rock.
The technical specs and the recommended retail price of the discussed cooling solutions are given in the table below:
Considering the design peculiarities of our today’s testing participants, we will test them only in a closed testbed with the mainboard in vertical position.
Our testbed was identical for all coolers and featured the following configuration:
As usual, using the weakest cooling system of our today’s testing participants we managed to overclock our quad-core processor to 3.38GHz with the Vcore increased to 1.53 75V in the mainboard BIOS. The monitoring utilities reported the core voltage setting a little bit lower than what was set in the mainboard BIOS: around 1.5~1.5125V. The system memory was working at 980MHz efficient frequency with 5-5-5-14_2T timings and 2.05V voltage.
All tests were performed under Windows XP Professional Edition SP2. SpeedFan 4.34 Beta 40 was used to monitor the temperature of the CPU, reading it directly from the CPU core sensor:
The mainboard’s automatic fan speed management feature was disabled for the time of the tests in the mainboard BIOS. The CPU thermal throttling was controlled with the new RightMark CPU Clock Utility version 2.35.0:
The CPU was heated up with OCCT (OverClock Checking Tool) version 2.0.0 in a 23-minute test with maximum CPU utilization, during which the system remained idle in the first and last 4 minutes of the test:
I performed at least two cycles of tests and waited for approximately 20 minutes for the temperature inside the system case to stabilize during each test cycle. The stabilization period in an open testbed took about half the time. The maximum temperature of the hottest CPU core of the four in the two test cycles was considered the final result (if the difference was no bigger than 1°C – otherwise the test was performed at least once again). Despite the stabilization period, the result of the second test cycle was usually 0.5-1°C higher.
The ambient temperature was checked next to the system case with an electronic thermometer that allows monitoring the temperature changes over the past 6 hours. During our test session room temperatures varied between 24.5 ~ 25°C. It is used as a staring point on the diagrams. Note that the fan rotation speeds as shown in the diagrams are the average readings reported by SpeedFan, and not the official claimed fan specifications.
The noise level of each cooler was measured according to our traditional method described in the previous articles with the help of an electronic noise meter – CENTER-321. The subjectively comfortable noise level was considered 34.5dBA and is marked with a dotted line in the diagram. The ambient noise from the system case without the CPU cooler didn’t exceed 33.2dBA when measured at 1m distance.
It is rally hard to tell what cooling solution could be considered the best competitor to our today’s unusual testing participants. It is not logical to compare their performance against that of a traditional liquid-cooling system, because any more or less efficient solution costs more than all three today’s coolers together. And if we go for an air cooler, then which one should that be? Judging by the price, we should go for a $45-$50 cooler, so we decided to compare the performance of our today’s unique cooling solutions against that of a not very expensive, but very efficient ZEROtherm NV120 Premium cooler, which you may have already read about on our site.
The results obtained during our test session are given on the diagram below:
And again, no wonder happened. In fact, what happened was a pretty usual thing for compact cooling systems: they lost to a decent air cooler indisputably. And today’s defeat is honestly a real fiasco for all three cooling solutions tested, because losing 13ºC even to a very efficient air cooler is an inexcusable mistake for innovative solutions and liquid-cooling systems. It may determine their future in a not the most favorable manner.
Nevertheless, I would still like to point out one of our testing participants specifically. It is Akasa Revo. At first, I really doubted that it would work at all, but then this practically weightless cooler turned out capable of dealing with an overclocked quad-core processor! The “magic bubble” system does work, though not as efficiently as we may have wanted it to. However, practice makes perfect.
Now let’s check out the results of our noise measurements.
We measured the level of noise generated by our today’s testing participants from a 3cm, 1m and 3m distance. The results are given on the diagram below:
The situation here is pretty sad, as you may see. Under peak workload none of the tested cooling systems remained within comfortable acoustic range and the noisiest one is XIGMATEK solution. The results obtained at minimal fan rotation speeds are not given here, because as you may have guessed, 92mm fans of the Akasa Revo and AURAS Conditioner as well as the 80mm fan of XIGMATEK AIO-S80DP rotating at around ~1100RPM or less will not be audible against the background noise from the rest of the system case. I would only like to add that I didn’t detect any motor crackling by any of the coolers.
The conclusions will be pretty simple today. To be more exact there can be only one conclusion: the cooling solutions we have just discussed will hardly be of any interest to overclocking fans. They are not efficient enough for the money and generate quite a bit of noise during work. So, what might attract a potential customer to these three CPU coolers? Compact size, universal design, simple installation and modding highlighting could be those features, although most cooling solutions using heatpipe design do have all these features too.
So, anyway, what is the sweet spot of these coolers? I believe they are good basis for future improved modifications that we might expect to see pretty soon. Such as Akasa Revo 2 with larger copper radiator for a 120-mm fan, enhanced heat-spreader with copper in it and a new advanced fan. So, we look forward to checking one of them out in the near future, and in the meanwhile, we, unfortunately, have to admit that the coolers we tested today fell victims to compactness and originality.