by Sergey Lepilov
10/06/2008 | 07:21 PM
If we look at contemporary tendencies in air cooling design, we will be able to conclude that they do not go with the times. Despite the brewing worldwide economic crisis, limited resources and attempts to save on everything, while automobiles are being equipped with hybrid engines, cooler manufacturers make their solutions bigger and provide them with even more heatpipes. As a result, cooling solutions become larger, heavier and more expensive, with a few rare exceptions. If we once again compare this situation with the car industry, namely Formula 1, we will see that they started to reduce the number of engine cylinders (10 instead of 12, and later maybe even 8), while cooler manufacturers, on the contrary, increase the number of heatpipes.
The most recent example is the new V8 and V10 coolers from Cooler Master that use 8 and 10 (!) heatpipes respectively. The latter will be tested in our upcoming articles, because Cooler Master V10 is scheduled to come out a little later. Today we are going to discuss an “8-cylinder” V8 cooler and test its efficiency, acoustic performance and other important features. As we already know from the tests of a gigantic 10-heatpipe Scythe Orochi cooler, the number of heatpipes and the size of the cooler do not play the most important role in its efficiency. However, Cooler Master engineers didn’t use the traditional extensive approach when working on their new cooler by simply increasing its size and weight. They in fact introduced a few very innovative ideas. But let’s get started from the very beginning.
Glossy box designed in strict black color indicates that the cooling system inside is going to be a very serious solution:
There is a top shot of the V8 cooler on the front of the box together with a promise to dissipate 180W of heat. The back of the box contains the description of the newcomer’s specifications and key features:
Inside the cardboard box the cooler is securely packed into a clear plastic casing that protects it against possible transportation damages. On one side of the plastic casing there is a flat box with accessories that include the following items:
Let me list them from left to right and from top to bottom:
Besides, the Cooler Master V8 bundle also includes a multi-lingual assembly and installation manual. According to the information on the box, the cooler is made in China. The cooler is already available in retain for $59+.
At first glance the cooler impresses with its extraordinary looks. Even experienced overclockers will be taken away by sophisticatedly twisted heatpipes and four aluminum heatsink arrays:
The device measures 120 x 128 x 161.1mm and weighs 865g. These parameters are comparable with the best air coolers out there. Cooler Master V8 is based on 8 copper heatpipes 6mm in diameter holding four aluminum heatsink arrays:
At first glance it is very hard to figure out what heatpipe goes where from the base of the cooler, so, let’s take a closer look at the cooler step by step:
Two heatpipes go through the center of the cooler base plate and then enter the middle of two main heatsink sections. They pierce the total of 116 (2 x 58) aluminum plates:
The copper base plate is the thinnest beneath the two central heatpipes: it measures 3mm. If we keep moving away from the center of the base towards the sides, the next pair of heatpipes leads to the lower part of two additional heatsinks sitting behind the main ones with the plates positioned perpendicularly. These two “attached” sections consist of 38 plates each. The plates positioned perpendicularly to those of the main heatsink arrays will definitely create additional resistance to the fan airflow. The copper base plate beneath these two heatpipes measures 4.5mm.
The next pair of heatpipes closer to the sides also leads to the additional heatsinks. However, they pierce their top part, not bottom:
The copper base plate beneath these two heatpipes measures 8mm.
The remaining two heatpipes are not even in the base of the cooler anymore, but on a small shelf for the retention (see picture above). They enter the sides of the min heatsinks piercing 48 plates on each side:
Let’s sum up everything we know about the heatsink. Cooler Master V8 consists of 8 heatpipes, two main heatsink arrays (48+10 aluminum plates in each) and two additional arrays (38 plates in each). Pretty massive solution, isn’t it? Here I would like to add that the plates are spaced out equally at 2mm in all parts of the heatsink, and are 0.25~0.3mm thick.
Even if I forgot to mention something about the design of the new Cooler Master V8, the photo below should help better understand the way heatpipes are positioned:
The internal sides of two main heatsink arrays are slightly concaved:
It may have been done to reduce the airflow resistance, which increases significantly once the airflow leaves the main heatsink array. The minimal distance between the arrays is 27mm, so no alterative fans 32mm or 38mm deep will fit in there, unless you are going to bend the heatpipes and push the heatsink arrays farther away yourself.
There is a fan that goes right between the additional heatsink arrays. The fan is then covered with a plastic top:
The top is attached with four thumb screws and bears the manufacturer’s logo and the fan model name.
The fan attaches to the top with four plastic clips, so it is very simple to replace the fan with a new one if it breaks or if you find something more efficient. Cooler Master V8 uses Cooler Master R4-C2R-20AC-GP fan, just like Cooler Master Hyper 212 and GeminII S coolers as well as Cosmos cases. It measures 120 x 120 x 25mm and has 9 blades:
What is the fan rotation speed? According to the specifications, it is PWM controlled in the ~800~1800RPM range. However, as far as I understood, the maximum value may be set manually using the rotation speed controller that may be installed on the case rear panel using the bundled bracket:
In this case the noise level should be higher than ~17dBA, which is hardly true in reality. The claimed fan MTBF is 40,000 hours (slide bearing). At maximum rotation speed the fan creates 2.94 mmH2O air pressure at 69.69CFM airflow.
There are two red LEDs in the upper part of the fan:
However, when the fan is working, you can barely see the LEDs through the slits in the plastic top cover.
The cooler base is finished pretty decently. Though there are visible machine marks on it, you don’t really feel them to the touch.
If you are fond of mirror-shining base surfaces, then you will have to work on it yourself. But the base is very even, so no effort needs to be applied here:
You can find Cooler Master V8 step-by-step installation instructions in the electronic manual (PDF file, 3.01MB). In the current part of our article we will only dwell on a few key things about installation. First, the cooler is attached through the mainboard PCB, so you will have to remove it from the system case. The V8 cooler fits on any of the contemporary platforms. Before installation, you have to attach the appropriate retention plates to the cooler base with bundled screws:
Just like by the recently reviewed Cooler Master GeminII S, you insert rotating counterclockwise two or four spindles (depending on the socket type) into the loops of the retention plates and stick special rubber rings to them that will protect the mainboard PCB from damage when the cooler is installed:
Second, I have already had enough experience with Cooler Master coolers and I am convinced that it is much more convenient to install the mainboard onto the cooler and not the other way around. So, let’s turn V8 upside down and set the board onto the spindles. After that you fasten the backplate to the cooler through the mainboard PCB with bundled screw nuts:
You should use the enclosed wrench, but it nearly slides off all the time, because of the backplate edges. I believe the engineers should have thought of something better here. Installing coolers through the mainboard PCB requires a little more skill and effort, than any other installation technique. However, it ensures the most secure contact between the cooler base and the CPU heat-spreader and provides the most efficient heat transfer.
Despite a lot of heatpipes, Cooler Master V8 is compact at the base and doesn’t interfere with any heatsinks in the area around the processor socket:
There are 44mm between the mainboard PCB and the lower heatsink plate. Despite its pretty large size, Cooler Master V8 fit perfectly into the system case and interfered neither with the tall memory DIMM heat-spreaders, nor with the chipset North Bridge heatsink:
As you can see from the photo above, the cooler is installed in such a way that all its heatpipes are turned horizontally and the airflow from the fan is directed towards the system PSU fan. Our tests showed that in this case Cooler Master V8 cools the CPU 3ºC worse than in case the airflow from its fan is directed towards the case rear panel. The difference is small, but we once again confirmed it during the second round of tests. In an open testbed with the cooler installed vertically, no differences depending on the positioning have been detected.
The technical specifications and recommended pricing of the new Cooler Master V8 are summed up in the table below:
We tested the new V8 cooler in two modes: in an open testbed when the mainboard sits horizontally on the desk and the cooler is installed vertically, and in a closed testbed with the mainboard in vertical position.
Our testbed was identical for all coolers and featured the following configuration:
All tests were performed under Windows Vista Ultimate Edition x86 SP1. SpeedFan 4.34 was used to monitor the temperature of the CPU and mainboard, reading it directly from the CPU core sensor and to monitor the rotation speed of the cooler fans:
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 RightMark CPU Clock Utility version 2.35.0:
The CPU was heated up in two modes. First we used Linpack 32-bit with very useful LinX shell to heat it up to its maximum. We manually set the RAM capacity at 1200MB and recorded 13 runs.
Since we ran the test twice with 20-minute idle period between the runs for the system to cool down and temperatures to stabilize, the relatively short actual testing period was quite enough for the maximum processor temperature to become stable. The complete screenshot from the test run is given below:
Since Linpack generates not quite typical workload for the CPU, which you will hardly come across in any other application, we decided to also test our system in a very resource-hungry game – Unreal Tournament 3 - that works with all four processor cores.
During the test the “Fly By” scene was run 5 times at “DM-ShangriLa” level wit the help of HardwareOC UT3 Bench v188.8.131.52 benchmark. To minimize the dependence of the CPU performance on the not very fast graphics card in our system we used 800x600 resolution and average image quality settings.
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. Despite the stabilization period, the result of the second test cycle was usually 0.5-1°C higher. 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).
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 25.0°C. It is used as a staring point on the temperature 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.
We will be comparing the cooling efficiency of the Cooler Master V8 against another tower cooler Thermalright Ultra-120 eXtreme (~$60) equipped with a single Scythe Slip Stream 120 fan (~$8) in two modes: at 900RPM and at the maximum speed of ~2030RPM.
During Linpack tests inside a closed system case using the “weakest” cooling system of the two we managed to overclock our 45nm quad-core processor to 3.81GHz (+27%). The nominal processor Vcore was increased to ~1.53V in the mainboard BIOS (+24%):
During Unreal Tournament 3 tests both coolers ensured processor stability at almost maximum possible overclocking up to 4.02GHz and 1.55V Vcore.
The results are summed up on the diagram below:
Well, the new Cooler Master V8 proved very confident in our tests. Yes, it did lose to its main competitor in the quiet mode as well as at maximum fan rotation speed. However, the difference is not that dramatic. On the contrary, it is great to yield only 1-3ºC to the performance leader among contemporary air coolers. With an insignificant cooling efficiency difference like that we have to consider other factors when deciding between the two coolers, such as availability and price. As for the availability, Cooler Master solutions are way wider spread than Thermalright ones. However, as for the price, the current retail pricing may scare away some of the potential buyers. Besides, from the overclocking standpoint, Thermalright Ultra-120 eXtreme may accommodate a second fan and retain its high efficiency at a low level of generated noise. However, modifying Cooler Master V8 may be hard to accomplish (replacing the fan doesn’t count).
Nevertheless, I personally liked the cooler a lot. This is a product of extremely high quality, with reliable retention, smart design (so there won’t be any compatibility issues), very quiet operation at minimal fan rotation speed and moderate level of noise at maximum fan rotation speed, and with its own unique extraordinary looks. Is there anything that could be improved about it? It is really hard to tell, I would probably try repositioning the heatpipes inside the heatsink arrays, so that not only the two middle ones but also the next two heatpipes could bear the maximum thermal load – they would have to go into the main heatsink arrays, and not into the additional ones. Moreover, keeping in mind the plates density and intersecting heatsinks, I would suggest that they should experiment with 38-mm fans featuring higher air pressure than 25mm ones. Although in this case they will have to push the central heatsink arrays a little more apart.
And one more thing I have to point out in our today’s review. Everyone knows that this November Intel will launch Core i7 (Bloomfield) processor in LGA 1366 form-factor. As I have found out, the LGA775 coolers will not be compatible with the new socket, so we should at least see new modifications of existing models and maybe even a new span of competition between cooling solutions for the new processors. So, if you already own a certain cooler of those we have tested at Xbit Labs and are planning to upgrade your platform in the near future, the new solutions like Cooler Master V8 may be of purely theoretical interest to you, unfortunately. Anyway, as always, the choice is yours :)
UPDATE: As we have just learned from Cooler Master, V8 cooler will be one of the recommended cooling solutions from Intel for the new Nehalem / Core i7. The incoming shipments will include a bracket for socket LGA 1366.