Thermaltake ProWater 850i Liquid Cooler

Using our trusted T.E.C.C. testing methods, we compare Thermaltake's ProWater 850i to all our previously tested coolers.
Published Mon, Jun 9 2008 11:00 PM CDT   |   Updated Fri, Sep 18 2020 10:50 PM CDT
Rating: 92%Manufacturer: Thermaltake


Water cooling, no longer the black art or taboo form of cooling PC components where only the James Dean of computer users dared go. Over time water cooling evolved from clumsy homemade pieces made from parts purchased at auto part and home improvement stores to commercial, mass produced components as refined as motherboards and processors.

Thermaltake played a large role in the evolution of the water-cooling phenomenon. With their manufacturing capability and R&D teams, the company has made improvements in the quality of components used and the level of skill needed to install a unit successfully.

Thermaltake's best selling water cooling kits, the BigWater Series are well known for their ease of use and relative low cost when compared to several of the "Pro" kits by companies like Swiftech and Danger Den. Thermaltake has changed the formula to manufacture a pro level kit of their own, and the series is called ProWater. Today we are going to look at the ProWater 850i, a component based kit that is still an all-in-one solution but uses traditional parts found only on more expensive kits.

Specifications, Availability and Pricing

Water cooling kits are made from several components. In most cases these components can be swapped with other components, and you can even add more water blocks to cool chipsets and graphics cards.

The ProWater 850i water block comes with mounting hardware to fit the above applications. The block is very diverse and works with both modern AMD and Intel systems.

The block uses 3/8 inch tubing and is made of copper. Some consider the waterblock to be the most important part of a water cooling system. The block has the responsibility of pulling the heat from the processor and distributing it to the water passing through.

For me and those that have been running water cooling for a long period of time, we realize that the radiator, in terms of the kits ability to cool your components, is the most important part of the entire kit. As water passes through the water block it picks up heat from the processor, but without a way to cool the water, the heat would build. It takes a little longer but the end result would be like running a traditional CPU cooler without a fan or any internal case air flow.

While the radiator makes heat available to the outside air, a fan still has to get the air out of the radiator. The design of the radiator directly relates to the type of fan used. If the cooling fins on the radiator are tight together, the fan has to be able to push past all of those restrictions. If the fins are farther apart, the fan can spin slower, push less air and the end result is making less noise.

Pumps for water cooling systems come in all shapes, sizes and intended applications. It has been debated repeatedly as to whether or not a pump that moves water faster is better for cooling PC components. This is one of the best points of buying an all-in-one kit system; the pump is made for that system and end users don't have to guess on the amount of flow needed.

The more water or coolant in a loop, the better! The component used to store idle coolant is the tank or reservoir. As coolant passes through the block, it picks up heat which raises the temperature of the coolant. Most of the heat is dispelled through the radiator, but a small amount of is retained in the coolant. The more coolant you have in the loop, the less the temperature changes as the overall volume is able to absorb the heat and disperse it over a larger area.

The tubing that Thermaltake uses for their ProWater 850i is a UV reactive type that is 3/8 inch in diameter. When used with a black light, the tube reacts and gives off a green glow.

The ProWater 850i includes a 500cc bottle of Propylene Glycol, an industrial coolant that is less toxic than standard antifreeze. It is important to remember to NEVER USE TAP WATER in your cooling system. Tap water contains many contaminates that will eat away at the copper in the base and aluminum radiator. Even with distilled water, the water will cause a chemical reaction with the copper and aluminum causing your system to become less efficient.

Thermaltake has products in every store that sells computer components, and is one of the largest manufacturers of computer accessories. The 850i is a new kit; currently the system is available from just a couple of e-tail locations, but the list is growing. The MSRP of the 850i is set at 149.99 US Dollars, but I was able to find the kit for as low as 119.00 here in the US.


The Package

The Thermaltake ProWater 850i package has a large window that allows you to see several of the components from the kit.

The side shows the specifications for all of the components that are included with the kit.

The rear of the case has images of all of the components and a small description of their function.

The other side shows the feature list of the PW 850i as well as a general description of the system.

The system is held in place with high density foam that does not allow any of the components to move around and get damaged during shipping.

The ProWater 850i

Thermaltake used a copper block for the PW 850i and as you can see here, the block supports several processor and motherboard types. The top mount is attached to the base with two screws making perfect CPU alignment very easy.

The base of the block has a near mirror finish that is visually smooth. The raised area in the center will allow better contact with the CPU since most processors have a slight curve on their Integrated Heat Spreader (IHS) that can reduce the amount of contact with the cooler.

The radiator uses a standard 120mm fan to push air out of the radiator. The fan uses a 4-pin Molex connector for power but also has a 3-pin motherboard fan connector for fan tachometer use only.

When mounting the radiator it is best to align it so that the water comes out of the top; this is so air does not get trapped in the radiator, reducing coolant to radiator contact.

Here you see the 120mm fan and the radiator from the side. The radiator is a single row configuration that does not take up much room inside of your system and can be easily mounted to the rear or top 120mm fan hole. You want the air to blow out of the case, this way you are not raising the ambient case temperature.

On the back side of the radiator we found a bracket that allows for easy mounting of the radiator to the case. I generally move the fan to the other side of the radiator so the fan sits between the case and radiator, giving a little cleaner appearance.

This configuration pulls air through the radiator instead of pushing it, and allows air to pass over a larger area of fins at the cost of a slower volume of air passing over. This also guarantees that all of the contaminated air exits the case instead of some of it being deflected back into the case.

The ProWater 850i Continued

The pump and reservoir are attached from the factory. On the reservoir, you will find a fill port at the top and a return port for the water coming back to the start of the system. Notice the low and high marks. It is important to always keep fluid above the low level. If not, the returning cooling will splash into the other liquid and allow air to pass through the system.

The pump is a small impeller type that pulls coolant from the reservoir and pushes it up through the cooling loop. The pump uses the same connectors as the fan; a 4-pin Molex for power and a 3-pin fan for tachometer use only.

Many water cooling systems are silent to the point where it is difficult to know if the system is actually pushing fluid through the loop. Thermaltake makes it easy to give you peace of mind with their device that allows you to see that coolant is flowing through the system.

The PW 850i comes with enough tubing and coolant to use the system in the largest cases. Both items react to UV black lights and glow a neon green color. It is important to remember to use only the amount of tubing needed for your application. More tube means the pump has to work harder to pass the fluid through the system, reducing flow.

Accessories and Documentation

Looking closely at the parts bags, they are marked with letters and the manual tells you what parts, from which bag are needed to mount your system for each processor type. The coiled plastic above the parts bags is to wrap around the tubing and it reinforces the tubing so it does not kink when bent at extreme angles.

The PW 850i manual is actually a book that gives a detailed description of the components, their use and how to mount them. Since many first time water cooling enthusiasts choose to purchase an all-in-one kit, it is important to have good instructions available. The 850i gets the tick of approval here.

Testing Results

Test Results

TweakTown uses a different method for testing CPU heatsinks which allows for an even playing field across all product tests. We feel that by using the same ambient temperature and strict lab-like testing procedures we are able to accurately compare one product to another. More information on our testing procedure can be found in the T.E.C.C. article here.

One of the best things about water cooling is that your system processor temperatures do not fluctuate a great deal between idle and load. This becomes important when overclocking because you want a solid temperature so that your system doesn't crash when it is being pushed harder.

The Thermaltake ProWater 850i does a really good job of keeping the idle and load temperatures very close together, giving you a solid foundation for achieving a stable overclocked processor. The single 120mm radiator unit is holding the system back a little; a dual 120mm radiator would be able to hold the temperature a little lower and a little more stable.

The fan with the ProWater 850i is user adjustable and uses a 4-pin Molex connector, so you will not be able to take advantage on your motherboards built in 3-pin power circuitry that would raise and lower the fan speed as needed when the processor temperature reaches a set point. Since we test the cooling fans at their full 12-volts under load and 7-volts at idle, the test takes the user adjustability out of the equation for the sake of achieving the most accurate Thermal Test. In real world practice the users can set the fans to their liking, which all but eliminates the SPL test, other than the best thermal performance settings.

When the Thermaltake PW 850i is set to just above audible levels, the entire cooling system is very quiet in relation to other CPU coolers we have tested. Thermal performance is lowered a small amount, around 4 degrees Celsius at load.

The coolant pump on the PW 850i can be the loudest part of the cooling system if left sitting on the bottom of the case. The pump has a vibration and will resinate through the entire case, amplifying the external sound you hear. To eliminate this, take an old or new foam mouse pad and cut it to make a base for the pump system to rest on.

Final Thoughts

The Thermaltake ProWater 850i is a step above the company's entry level water cooling kits and is a good choice for those looking for stable performance with a low acoustic footprint. The fan is able to crank up to very high speeds, giving overclockers who are less worried about noise and more focused on performance the opportunity to let their system run wild.

The construction of the components in the system are above average quality and everything fits together nicely. Thermaltake has loaded the PW 850i with enough UV reactive tubing to ensure a smooth build while dressing up the look of what would otherwise be just another kitted water cooling system.

Overall, the Thermaltake Pro Water 850i has everything a first time or above average computer user would want to find in a pre-built component kit. Enthusiasts looking to pull the most out of their system will opt for individual components to achieve the best possible performance of all their parts, but at a much larger, pro level price.

What do TweakTown awards and ratings mean? Click!

PRICING: You can find products similar to this one for sale below.

USUnited States: Find other tech and computer products like this over at

UKUnited Kingdom: Find other tech and computer products like this over at

AUAustralia: Find other tech and computer products like this over at

CACanada: Find other tech and computer products like this over at

DEDeutschland: Finde andere Technik- und Computerprodukte wie dieses auf

Chris Ramseyer started his career as a LAN Party organizer in Midwest USA. After working with several computer companies he was asked to join the team at The Adrenaline Vault by fellow Midwest LAN Party legend Sean Aikins. After a series of shake ups at AVault, Chris eventually took over as Editor-in-Chief before leaving to start Real World Entertainment. Look for Chris to bring his unique methods of testing Hard Disk Drives, Solid State Drives as well as RAID controller and NAS boxes to TweakTown as he looks to provide an accurate test bed to make your purchasing decisions easier.

We openly invite the companies who provide us with review samples / who are mentioned or discussed to express their opinion. If any company representative wishes to respond, we will publish the response here. Please contact us if you wish to respond.
Newsletter Subscription

Latest News

View More News

Latest Reviews

View More Reviews

Latest Articles

View More Articles