by Sergey Lepilov
12/31/2007 | 09:57 AM
I believe that these days it is impossible to set up an efficient PC liquid-cooling system that would fit inside a standard ATX system case. Remember, how many internal liquid-cooling systems we tested so far and what results we obtained in our tests and you will get the point. And it is not only the inefficient water blocks or weak pumps that determine the efficiency of these solutions. There seems to be a different reason for that.
The actual operational principle of the liquid-cooling systems is based on transferring the heat away from its source and its rapid dissipation. And if the first one can be achieved with an efficient water block and a powerful pump, then the second one is hardly possible to fulfill inside a standard ATX system case, even a very roomy one. There is simply not enough room in there for a heatsink topped with two 120x120x25mm fans, and even if you manage to squeeze it in, the hot air will not go anywhere and will stay inside. Of course, there are some systems that allow installing heatsinks on the case rear or side panel. However, these liquid-cooling systems use either a single 120mm fan (such as Cooler Master Aquagate Mini R120) or two 70x15mm fans (Cooler Master Aquagate Viva). And our tests showed, that this is obviously not enough.
Nevertheless, convenience of use, exterior looks and universal design seem to dominate over efficiency and noise in mass liquid-cooling systems these days. Looks like the marketing departments of these companies turn out more powerful than their engineering teams. So, today we are going to talk about a new liquid-cooling system from Thermaltake that… But let’s not jump ahead of time and start from the very beginning :)
The new liquid-cooling system comes in a large colorful box with a plastic carry handle:
There is a photograph of the system built into the PC case on the front of the box together with a brief list of its advantages. The reverse side contains its detailed specifications, features description and other less important stuff.
Inside the box all the system components are separated into individual plastic foam sections:
A vivid-green tube 9.5mm in diameter lies on top of it:
The tube is a little less than 4 meters long and it is more than enough to build the cooling system not only for the CPU, but also for all other system components, including the mouse and USB flash drive :) Besides, the tube glows in UV light.
There is a plastic bag with a retention kit in a separate section. This kit is very similar to Thermaltake Big Typhoon retention from the constructive standpoint. It also includes a number of clamps and some thermal compound:
Besides, the bundle also includes two thick instructions manuals:
One of them is an installation and connection guide, and another one – user’s manual.
The package also contains a full 0.5 l bottle of coolant:
The main component of this coolant is propylene glycol with anticorrosion additives. The bottle is boxed separately, which means that you can purchase it without the system itself.
The last thing bundled with the system is an additional bottle of coolant for system refill:
It is equipped with a special tube that should ease the filling process.
The main block of the cooling system looks like a box with a meshed window on the front that fits into two five-inch bays of the system case:
The designers intended this window to serve for air intake by the 120-mm fan inside. The block is 232mm x 148.6mm x 85mm big.
Let’s take a look at this block from the top:
It consists of an aluminum radiator with a 120mm fan on top of it, an expansion tank and a pump. All components are connected with one another using hard plastic tubes:
The aluminum radiator is 153mm x 120mm x 28mm in size. Thermaltake engineers employed “Dimple Tube” technology for their radiator design. It implies that the internal radiator canals feature small grooves. This is what it looks like, according to the manufacturer:
These round grooves should create additional turbulence for the airflow, a solution we have already come across in a heatsink of the OCZ air cooler. It is hardly possible to check whether this solution improves heat dissipation, so all we can do is take the manufacturer’s word for it. I would like to add that the radiator is cooled with a 120mm x 120mm x 25mm fan with variable rotation speed and blue highlighting. The fan rotation sped can vary in the interval from 1600RPM to 2400RPM with the claimed noise level of 16-20dBA.
The expansion tank is 72.4mm x 70.5mm x 69.4mm big with 130ml capacity:
There is a plastic plug on top of it that can be opened to add coolant to the system. The two marks on the sides indicate the minimum and maximum levels of coolant in the system.
Thermaltake Big Water 760i is equipped with P500 pump with claimed maximum flow rate of 500 l/h (allowed deviation ±50 l/h). We managed to find some additional technical specs of the pump on the inside of it:
One of the most interesting ones is maximum head of 1.8m, which is not bad at all for a mass liquid-cooling system. The use of a ceramic bearing for the pump allowed the manufacturer to claim its MTBF of 80,000 hours which is more than 9 years. The level of generated noise is claimed to be 16dBA, but Thermaltake traditionally lowers this particular specification of their products, so we wouldn’t take it for granted right away.
There are inbound and outbound tubes, two Molex power connectors, fan rotation speed tachometer connector and fan rotation speed regulator coming out of the main liquid-cooling system block:
The tubes coming out of the pump and expansion tank end with special valves that will be connected to the corresponding valves on the ends of the water block tubes:
Thanks to this simple and pretty reliable connection, the system is very easy to assemble and move around.
The water block has the universal retention already preinstalled. This retention fits for both: Socket 478 and LGA 775 mainboards as well as for mainboards designed for K8 platform:
According to the manufacturer, the copper water block features micro-channel internal design:
The water block base is not covered with any protective layer. It boasts pretty decent finish quality, although lacks Thermaltake’s traditional mirror-shine polishing:
The base is impeccably even, we checked it using a thermal compound print method. We discovered no bumps or gaps whatsoever.
The system is extremely easy to put together. Nevertheless, you will have to remove the mainboard from the system case before you start. You need it to insert the water block retention spindles around the processor socket through the holes in the mainboard PCB:
Then you install the backplate with soft padding on the bottom of the board. And after that all you need to do is place the water block onto the spindles and tighten it up using shaped crew nuts with washers:
Note that the LGA 775 platform allows turning the water block in any direction as the installation manual doesn’t mention any preferred positioning of the water block on top of the CPU.
Don’t be surprised to see two different mainboards on the photos above. The thing is that Thermaltake Big Water 760i was tested on two different platforms, so this is where the differences come from.
Now a few words about the main unit of the liquid-cooling system. Thermaltake engineers suggested that the ideal location for it would be the top five-inch bays of the Thermaltake Armor system case:
In this case, the airflow can easily get to the cooling system fan. However, very few users can boast owning these expensive cases (particularly this model), so the majority will have to install this unit into any two available five-inch bays (if there are any). In this case the air flow should hit the fan through the front bezel mesh, which is a pretty doubtful idea, since the fan is almost leveled with the top panel of the main unit.
So, without much sophistication, I simply put the unit on top of the system case:
The tubes leading to this unit were connected through the back panel of the system case, while the power cables and fan rotation speed regulator had to go through the side of the case, because of insufficient cable length:
As a result, the airflow could travel freely to the main unit, but I couldn’t close the side case panel, because of the power and monitoring cables.
So, if you decided to place your Thermaltake Big Water 760i cooling system inside the case, keep in mind that you need to have a pretty roomy case (at least much roomier than the ASUS ASCOT 6AR2-B I had). Note, that the fan rotation speed monitoring is not very conveniently implemented, because you will have to get inside the system to adjust it. I wonder why they didn’t lay it out on the front panel? I would also like to add that the tubes were cut to 45-50cm length, so that they could lead directly to the unit, nothing more.
You can find step-by-step installation instructions on the official company web-site.
The technical specifications of Thermaltake Big Water 760i liquid-cooling system are given in the table below:
The new Thermaltake cooling system and its only opponent were tested in the following system:
The quad-core Intel Core 2 Quad Q6600 (2400MHz) processor with polished-off heat-spreader was overclocked to its maximum frequency with the today’s tested liquid-cooling system running in the quietest fan mode. The resulting frequency was 3267MHz at core voltage increased to 1.5V:
According to monitoring data from CPU-Z, SpeedFan and Everest, processor Vcore equaled 1.47V. Vdimm was increased to 2.25V, and other mainboard voltages remained default. CPU Voltage Reference parameter was set at 0.63x in the mainboard BIOS, and CPU Voltage Damper – enabled. The automatic fan rotation speed control system (Q-Fan) was disabled in the mainboard BIOS.
All tests are performed in Windows XP Professional Edition Service Pack 2. SpeedFan 4.34 Beta 34 was used to monitor the temperature of the CPU, reading it from the CPU core sensor. I would like to point out specifically that the new version of this utility has significantly corrected processor temperature readings towards higher values. So, compared with the previous SpeedFan version 4.33 the processor temperature readings rose by 18-19ºC.
The data from SpeedFan matched the readings from Core Tempt v0.95 utility. The thermal throttling of our test CPU activated at 100 ºC (determined empirically). For our Intel Core 2 Quad processor it was controlled with RightMark CPU Clock Utility version 2.30.
The CPU was heated up with OverClock Checking Tool version 1.1.1b in a 60-minute test with maximum CPU utilization, during which the system remained idle in the first and last 4 minutes:
I performed at least two cycles of tests and waited for 20 minutes for the temperature inside the system case to stabilize during each test cycle (the case side panel was open). For the above mentioned reasons we didn’t run any tests in an open testbed. The maximum temperature of the hottest CPU core in the two test cycles was considered as the final result (if the difference was not bigger than 1°C – otherwise the test was performed at least once again). Despite the stabilization period, the result of the second cycle was usually 0.5-1°C higher.
The noise level of each cooling system was measured according to our traditional method described in the previous articles. The subjectively comfortable level of 36dBA is marked with a dotted line in the diagram; the ambient noise from the system case, without the CPU cooler, didn’t exceed 34dBA when measured at 1m distance.
The ambient temperature was monitored with an electronic thermometer that allows monitoring the temperature changes over the past 6 hours. During our test session room temperatures stabilized at around ~24°C. It is used as a staring point on the diagrams. Note that the fan rotation speeds for the liquid-cooling system and the processor cooler are shown in the diagrams as the average readings reported by SpeedFan, and not as the claimed fan specifications.
Since we are going to test the Big Water today, its opponent will be the Big Typhoon from Thermaltake, namely Thermaltake Big Typhoon 120 VX supercooler:
Juts like the liquid-cooling system the cooler was tested inside the system case with the open side panel, i.e. in identical conditions. We used two fan modes for Thermaltake Big Typhoon 120 VX: quiet mode (~1320rpm) and maximum efficiency mode (2000rpm).
First of all let’s check out the CPU thermal diagram:
What can I say here? Big Typhoon almost blew away Big Water. 14°C advantage of Thermaltake Big Typhoon 120 VX over Thermaltake Big Water 760i in quiet mode speaks for itself. I can only guess what could have happened if the systems had been installed inside a closed system case. Of course, the efficiency of the liquid-cooling solution increases dramatically as we raise the fan rotation speed, which indicates very weak radiator, which efficiency has been sacrificed for the sake of compact size.
As I have already mentioned above, we checked out the system performance with differently positioned processor cooling block, however, it didn’t affect the end result in any way. Moreover, we replaced the water block with a pretty efficient Zalman ZM-WB5 and at first the temperature readings were really lower. However as time went on, the temperatures hit the same numbers as with Thermaltake’s original block. So, we can state that the CPU water block has nothing to do with low cooling efficiency.
Supposing that the overclocked quad-core processor based on older core stepping is too hot for the Big Water 760i cooling system, I replaced the CPU with Intel Core 2 Duo E6400 (2.13GHz) and the mainboard with Gigabyte GA-X38-DQ6. However, it only dropped the temperature difference between the competitors down to 10°C, which is hardly acceptable for a liquid-cooling system competing against an air cooler. Moreover, the maximum CPU frequency when cooled with a liquid-cooling system equaled 3.45GHz, while with the Big Typhoon 120 VX air cooler it clocked to 3.62GHz.
In conclusion let’s check out the noise diagram:
Big Water 760i stays quite noisy even at minimal fan rotation speed, because of relatively noisy pump (in fact it was the pump noise that we registered at 39.4dBA at minimal fan rotation speed). At first, while not all the air has been ousted out of the system completely, the whole thing generates even more noise, but after 20-30 minutes it gets a little quieter. The pump is no longer distinguishable when the 120mm fan is running at its maximum speed of 2400rpm. So, unfortunately, we cannot consider any of the Thermaltake Big Water 760i’s working modes comfortable.
It is a little hard to figure out who might be the potential user of a system like Thermaltake Big Water 760i we have just discussed. These could be the lucky owners of large system cases, like Thermaltake Armor with meshed top ensuring free airflow to the fan on top of the main block radiator. Although they must not care about the noise, because the pump of this system is quite loud. What are the advantages of this system? Acceptable price compared with the rest of the liquid-cooling solutions out there and extremely simple assembly procedure. Universal design and compact size are also great advantages, although they are quite typical of almost all contemporary cooling solutions including a big number of liquid-cooling systems. But don’t get the impression that I didn’t like this system at all. This is not true. Any product deserves a market and will eventually find it, although Thermaltake Big water 760i will hardly become an overclocker’s choice.