by Sergey Lepilov
09/26/2007 | 10:50 PM
This year we have already tested and reviewed over twenty models of air coolers for CPUs from different price categories and with different cooling performance. The regularly updated and extended cooler market currently offers a broadest selection of models from a dozen of recognized brands. The competition is so tough that it’s quite a difficult task to make a choice basing only on such factors as performance and noise level.
Every announcement and every release brings us hope that the new product will be at least better than Thermaltake’s Big Typhoon that has become a kind of litmus paper for testing cooling solutions. This hope is often misplaced while the truly efficient coolers are very rare.
Founded in 1998, Auras Technology Co., Ltd used to focus on cooling solutions for servers. It produced low-profile heatsinks, various fans, simple and compact coolers, mainboard heatsinks and even cooling systems for notebooks.
But earlier this year Auras entered the workstation market releasing a whole family of air coolers for desktop computers. The model range is impressive as it already includes at least 5 interesting solutions, including a liquid cooling system. This massive onslaught on the highly competitive cooler market cannot be left unattended so we are offering you a review of four CPU coolers from Auras that are all based on heat pipe technology.
These models vary in design and pricing, covering the entire price range. It is going to be interesting to compare them between each other as well as with products from other manufacturers. In the following sections you’ll find a description of each model.
I will begin to explore the Auras series with the junior and inexpensive SLC-747 model. It comes in a small square cardboard box:
The package shows a photo of the cooler, its specs, supported platforms and other information. The following accessories included into the kit can be found at the top of the box:
The cooler design is simple. We have reviewed such coolers on our site before:
Four copper heat pipes with a diameter of 6mm go out of the copper base distributing the heat flow in the heatsink ribs that hang on the pipes. The Auras SLC-747 measures 111x108x71mm at only 380g of weight.
The pipes all lie in the same plane in the heatsink, i.e. linearly.
The heatsink is topped with a 92mm fan that cools the whole arrangement:
The top of the heatsink ribs has a wavy profile for less resistance to the airflow from the fan.
Like in any other cooler with heat pipe technology, the area of contact between the aluminum ribs and the copper pipes is enlarged by means of bottlenecks that formed when the ribs were being put on the pipes.
By the way, the aluminum of the ribs is very soft and bends easily.
The fan of the Auras SLC-747 is made by Yen Sun Tech and runs on two sleeve bearings.
The fan supporting the PWM regulation feature, its speed can be varied from 700 to 2400rpm at a max airflow of 47CFM. The manufacturer specifies a noise level of 23dBA, but does not mention at which rotation speed it was measured – the value doesn’t seem correct for the maximum 2400rpm. The fan motor also rattles rather irritatingly across all the rotation speeds.
The cooler’s base has a piece of polyethylene film to protect it against scratches.
I can’t say the cooler’s base is finished well: the traces of the milling machine are visible and perceptible by touch.
Those who like it tidy have got some work to do here. Anyway, the uniform trace of thermal grease on glass testified to the flatness of the copper base.
You hardly have to look into the manual to install the cooler on any platform it supports. It’s all simple and intuitive. You secure the appropriate fastener with four screws and hitch the cooler to the plastic socket frame (for Socket 754/939/940/AM2) or push it into the mounting holes on the mainboard (for LGA775). Don’t forget to remove the protective piece of film from the cooler’s base and apply some thermal grease on it beforehand.
Inside a system case the Auras SLC-747 looks like follows:
Although the cooler is compact, I found it could only be installed on my ASUS P5K Deluxe mainboard in one position as shown in the photos. Otherwise, either the tall heatsinks on the MOSFETs around the socket or the chipset heatsink would get in the way of the cooler’s pipes. On the other hand, it is not exclusively the cooler’s fault because there are few mainboards that have as many heatsinks and heat pipes as the ASUS P5K Deluxe. Moreover, the orientation of a cooler like Auras SLC-747 inside the system case is not as important as with tower-like coolers.
The recommended price of the Auras SLC-747 is $31.5 which seems to be the main drawback of this product. I think this price is overstated by about 35%. Running a little ahead, I should confess you can spend this money to buy not only a more efficient, but also a quieter, cooler.
The box with an Auras LPT-700 is two times the size of the previous cooler’s box because it is a tower-like model. The face side of the box shows a photo of the cooler. Its sides show you the cooler’s specs, an airflows scheme, and how to install a fan on the heatsink.
The accessories are packed separately at the top of the box. These are a back-plate for LGA775 mainboards, a sticker with an Auras logo, four spring-loaded screws, a syringe of thermal grease, and an installation manual.
Easy to see, fasteners for Socket 754/939/940/AM2 mainboards are not included with the cooler. There is actually another version of the cooler that has a fastening mechanism for K8 platforms and the discussed version is not universal, being only compatible with LGA775 mainboards.
The cooler design is typical for a tower-like cooler with heat pipes.
Although the official website claims this model to have 6 heat pipes, it actually has only three. Made from copper, the 6mm heat pipes go through the copper base. They carry thin and pliable aluminum plates covered with a metallic casing on the sides. The pipes are bent a little forward in the direction of airflow. Considering the position of the fan, this solution helped make the cooler more compact than if it had upright pipes with a fan above them. The cooler measures 68x94x138mm at 504g of weight (with a fan).
The mentioned casing carries a plastic frame that is the basis of the fastening mechanism.
Note that the frame is positioned in such a way that some of the airflow from the fan will go below the heatsink plates to cool the mainboard’s near-socket space. The cooler design doesn’t provide for changing the position of the plastic frame.
In the top part of the cooler you can see the soldered ends of the heat pipes and the plastic corset of the fan.
The fan is fixed with pins and two latches at the top and bottom of the frame.
The Auras LPT-700 employs a 92mm fan with seven translucent blades. It is manufactured by Y. S. Tech, too.
Running on two sleeve bearings, this fan is marked as “FD129225LB”. It is specified to have a variable speed from 700 to 2100rpm at 43CMF airflow and 22dBA noise. The fan lacks highlighting, but its motor rattles just like that of the previous model.
The cooler’s base is protected with film:
Its base is finished better than the base of the inexpensive SLC-747:
It is not polished off but there are no traces of the milling machine at least. The base is flat as I verified by looking at the trace of thermal grease on a piece of glass.
Our version of the Auras LPT-700 cooler is meant only for LGA775 mainboards. It is fastened to the mainboard with four screws along the perimeter of the aluminum frame in the bottom part of the cooler. The screws go into a robust back-plate so you have to take the mainboard out of the system case to perform this procedure. The springs in the screws produce a very strong pressure but the back-plate prevents the mainboard from bending. The fan has to be installed only after the cooler is secured on the mainboard. Otherwise the fan would only be a nuisance while you are tightening the screws.
There are no problems with the orientation of the cooler on the CPU socket because the mounting holes around LGA775 are symmetrical. No components on the mainboard will get in the cooler’s way because the bottom plate of the heatsink is about 40mm above the mainboard, and the fastening aluminum plate is rather compact.
The Auras LPT-700 has a recommended price of $33, i.e. only $1.5 less than the price of the SLC-747.
We are moving towards more serious models an overclocker may get interested in. The next model is called Auras LPT-709.
The package with this cooler is designed in the same style as the previous model’s, showing a photo of the cooler, its specs, supported platforms and features. There is also an additional temperature diagram telling you that not only the CPU temperature, but also the cooling of the mainboard’s near-socket elements is much better with the Auras LPT-709 as opposed to the boxed cooler.
The accessories lie in a special compartment at the top of the box:
While the two models discussed above belong to the mainstream class of air coolers, the Auras LPT-709 is a more respectable product even in its appearance.
It is beautiful. Its copper base, copper heat pipes and aluminum heatsink are nickel-plated to create a stern and stylish appearance.
The heatsink with a 92mm fan hangs on four 6mm heat pipes.
To put airflow to better use, the sides are made blank due to the curved-in ends of the ribs while the pipes that go out of the copper base are tilted towards the direction of airflow.
The cooler measures 92x86x140mm at only 415g of weight (with the fan).
The heatsinks ribs are shaped curiously:
According to the picture on the cooler packaging, this wing-like shape of the ribs ensures proper airflows inside the heatsink and reduces resistance to it.
I have seen something like that in the design of the Thermalright Ultra-120 Extreme cooler which eventually became the winner of our tests.
The Auras LPT-709 has a 92x25mm fan fastened by means of four soft plastic hangers with rubber inserts.
This fastening mechanism prevents vibration and noise level although few manufacturers use it.
The speed of the fan is regulated automatically by means of the mainboard’s PWM feature like with the two previous models.
The Auras LPT-709 (with the Auras AS9225MMF_XB fan model) is specified to have a variable speed of 800 to 2400rpm at a max airflow of 47CMF and 23dBA of noise. The fan has two ball bearings and blue highlighting. It doesn’t rattle as the two previous coolers do.
The heat pipes are flattened in the base and secured with a metallic bar from above.
It’s hard to tell how the contact between the heat pipes and the copper base is established because I could find no trace of solder or thermal glue.
After removing the film from the cooler’s base you can see its splendid finish:
To be absolutely exact, there are micro-cavities in the surface of the cooler base, which must have formed when the copper was being coated with nickel. But I think this negligible defect is going to be corrected by the thermal interface easily. The base is ideally flat.
The cooler is mounted on mainboards just as the Auras SLC-747. You take four screws and secure the appropriate fastener type on the mainboard and then either hitch the cooler to the plastic retention frame around the socket (for Socket 754/939/940/AM2) or insert the locks into the mainboard’s mounting holes (LGA775). Again, don’t forget to remove the protective film from the base and apply thermal grease.
The bottom rib of the heatsink and the fan are 50mm above the mainboard surface, so nothing should prevent you from installing the Auras LPT-709 on your mainboard. The cooler is actually very compact inside a system case:
Its recommended price is $40. We’ll see shortly if the product is worth the money.
Finally, here is the star of this review. The Auras CTC-868 looks like a Zalman CNPS9700/9500 LED but has at least two distinctive features.
The largest box among the tested coolers shares its design style with the two previous models.
New on this particular box is a small diagram that compares the performance and noise of the Auras CTC-868 with the boxed cooler from Intel. The Auras is claimed to be 9°C more effective and 15dBA quieter. These numbers do not impress me.
The accessories to this cooler as the same as included with the LPT-709:
Added to them is a small manual on unfolding the cooler as I’ll explain shortly.
Here it is, the Auras CTC-868:
The cooler seems to be nothing else but a Zalman CNPS9500/9700 LED at first sight, but you can spot its unique features on closer inspection:
There are four copper heat pipes (6mm in diameter) going out of the copper base, and there are a lot of thin aluminum plates that form three sections of the heatsink: two unfolding side sections that have one heat pipe each while the central, stationary, part of the heatsink hangs on two heat pipes.
It is a rather questionable solution since there are two pipes pumping heat into the smallest heatsink while the larger, side heatsinks are serviced by only one pipe each.
The central heatsink is fixed on the cooler’s base while the side sections can be unfolded:
The pipes do not wobble and you have to apply some pressure to tilt the sections of the heatsink. However, the reliability of the whole arrangement and, more importantly, the efficiency of the heat transfer between the moving pipes and the base are questionable. We’ll see how it works in the Tests section.
The mechanism of fixing the tilted heat pipes in place is located in the cooler’s bottom part.
You should use the third retention hole for Intel CPUs and the second hole for AMD CPUs:
I don’t quite understand these limitations because the tilt of the side sections of the heatsink can only be limited by some near-socket components like heatsinks on power elements or memory modules. I don’t think this has any relation to the specifics of heat generation of Intel and AMD CPUs.
I also have some concerns about the contact between the pipes and the heatsink ribs. Note that the heat pipe has contact with only 50% of the rib.
This method of contact is used for every heat pipe, including the medium pair. This simple solution proves to be not very effective in practice, though.
The Auras CTC-868 has two 92mm impellers installed for intake and exhaust.
The speed of these DY9225HLG_QC fans is varied from 800 to 2400rpm at a maximum noise of 21dBA. Each fan has two blue LEDs. The motors of the fans do not rattle.
The cooler’s base is protected with a piece of polyethylene film:
Its finish quality is astonishing:
It is also immaculately flat. Auras has done a good job on it.
The CTC-868 can be installed on any supported platform without your having to take the mainboard out of the system case. You just secure the appropriate fastener with four screws on the cooler and then mount the cooler on the CPU:
There is no limitation as to the positioning of the cooler on LGA775 but you have to choose only one of two possible variants, depending on the position of the socket’s retention frame, if you’ve got a platform for K8 processors.
The cooler is unfolded and folded up by means of two clips at its top part.
So, this is all simple and handy, but does it work? You’ll see in the Tests section. I can only add that the recommended price of the Auras CTC-868 is $55, which implies serious requirements to the cooler.
The following table lists the specs and recommended prices of the discussed coolers from Auras.
* - there is a model with a different retention for Socket 754/939/940 and Socket AM2
The Auras coolers and their opponents were tested on an open testbed as well as in a system case with the following configuration:
The CPU was overclocked to its maximum frequency on the weakest of the tested coolers. The resulting frequency was 3204MHz at a core voltage of 1.475V.
All tests are performed in Windows XP Professional Edition Service Pack 2. SpeedFan 4.32 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 1.1.0 in a 24-minute test during which the system remains idle in the first and last 4 minutes.
The mainboard’s automatic fan speed management is disabled for the time of the tests. The thermal throttling of the Intel Core 2 Duo processor is controlled with RightMark CPU Clock Utility version 2.25. Our CPU begins to skip clock cycles on reaching a temperature of 82°C and higher.
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.
The ambient temperature was monitored by means of an electric thermometer and remained at 25.5°C during the tests (marked with a vertical red line in the diagrams). The fan rotation speeds are shown in the diagrams as reported by monitoring tools. The ASUS P5K mainboard series does not support the pulse-width modulation feature to control the CPU fan, so I had to set the subjectively quiet mode for the Auras coolers by means of the SpeedFan program.
We had tested coolers designed like the Auras SLC-747, so I didn’t add a similar cooler into this test session, especially as the SLC-747 costs too high for coolers of its kind. The SLC-747 and the more interesting tower-like models LPT-700 and LPT-709 will be opposed in our today’s tests by the Cooler Master Hyper TX (at its maximum 1890rpm and at a quiet 1470rpm speed). The Auras CTC-868 will contend with the Zalman CNPS9700 LED (at a quiet 1670rpm and at a maximum 2800rpm) that has a similar shape and design.
First, let’s take a look at the temperature of the overclocked quad-core CPU.
The results of the Auras SLC-747 and LPT-700 are quite what you could expect from them. The Auras LPT-709 is a nice surprise as it features high cooling performance and is but slightly inferior to the Zalman CNPS9700 LED, which is about $30 more expensive, in the system case. The Auras CTC-868 is a rather mediocre cooler as it is not only worse than the junior LPT-709 but also than the twice cheaper Cooler Master Hyper TX.
Note that the CTC-868 improves its performance by about 5°C on the open testbed when its fan speed is increased. When tested in the unfolded form, the peak temperature was 3-4°C higher, which agrees with my supposition that it was the middle, stationary, part of the cooler, rather than the unfolding sides that had the maximum thermal load. I didn’t include the results of the CTC-868 with an unfolded heatsink into the diagram above due to their uselessness.
The table below shows the temperature data of the other CPU and mainboard sensors (Core 0 and 1, 2 and 3 results were identical, so there are only Core 0 and 2 data here).
I also found out the maximum CPU frequency I could achieve with each cooler. Here are the results:
The CPU voltage data didn’t fit into the diagram. The voltage was set differently in the maximum frequency test:
The Auras LPT-709 goes on giving out good results, even though it is somewhat inferior to the cheaper Hyper TX on an open testbed. The CTC-868 is somewhat better now, yet its price still seems to be too high for its performance. The Zalman CNPS9700 LED is beyond competition in both quiet and max speed modes just as a cooler of its class should be. I don’t think the coolers tested in this review should be compared with those we tested earlier because the testbed now uses a different mainboard that allows to reveal the full potential of a CPU with air cooling. For example, the Thermalright Ultra-120 eXtreme with two 120mm fans keeps the quad-core CPU stable at 3.55GHz with a voltage of 1.65V.
The next diagram shows the noise level of each cooler measured according to our traditional methodology described in the previous articles (the subjectively comfortable level of 36dBA is marked with a dash line; the ambient noise from the system case, without the CPU cooler, was about 34dBA):
There is nothing much to comment upon. Every cooler from Auras supports PWM regulation and can be made to work quietly. Their performance in the quiet mode and at the max speed has been shown above.
Our tests have shown that Auras SLC-747 and LPT-700 coolers haven't demonstrated any remarkable results. Their mediocre performance with an overclocked quad-core CPU and their rattling fans can hardly attract an overclocker. Moreover, their recommended price of over $30 doesn’t make them competitive on the market. On the other hand, there have been examples when the pricing of a product would be corrected after an unsuccessful debut. Perhaps it will be the case with these coolers, too.
The unfolding Auras CTC-868 is unfortunately the main disappointment of this review. At a recommended price of $55 its performance is inferior even to the twice cheaper Cooler Master Hyper TX, let alone the super-cooler. I guess the problem is not only with the moving side sections (I mean the contact with the pipes in the base) but also with the small area of contact between the pipes and the heatsink ribs. The medium heatsink with two heat pipes is also too small while having to cope with the biggest thermal load. Anyway, I think that modders who prefer original and attractive coolers may like the Auras CTC-868 as well.
Thus, the Auras LPT-709 model is in fact a really useful new product. With its four heat pipes, thought-through heatsink design, vibration-absorbing hanger of the fan and superb finish of the base the Auras LPT-709 can cool an overclocked CPU effectively even in the quiet mode. At the max speed it delivers the performance of a super-cooler even. The highlighting of the fan and the nickel plating of the whole cooler are going to be just as attractive in the system case as the unfolding halves of the CTC-868.
So, there is one brand more on the market of coolers for desktop computers and workstations. If Auras products find a short route to the market and the distributors aren’t too greedy, we’ll have an even broader choice of CPU coolers, which is of course good.