Temperature monitoring of the CPU by the main unit comes via a small, bulb-type thermistor. This needs to be taped to the bottom of the CPU cooling block using the supplied adhesive copper patch. The other end is attached to the expansion slot-mounted controller bracket from where the data is fed to the main unit, along with a 12v feed, using the supplied data/power cable.
The base of each block is made from solid copper plated with 21-carat gold to give a flawless mirror finish. The top of the blocks are moulded in a smoked amber coloured plastic that allows you to instantly check for blockages, sludge build-up and other potential problems. You can also see the myriad of spikes that are cast on the back of the copper base which increase the water-to-copper surface area and ultimately the thermal transmission efficiency. They also create a little turbulence, which is generally believed to increase the ability of the water to draw away heat.
The CPU block is rated to an impressive 300W, so it should still be suitable for some of the monstrously warm CPUs due on the scene in the coming years.
Both the VGA and chipset blocks mount in a similar fashion to the CPU one, but have fixed length screws rather than ratcheted screws. The chipset block poses the greatest challenge for newer users in that it typically involves removing the motherboard so that the mounting screws can be inserted from the back. The chipset and VGA blocks are identical except for the VGA blockâ€™s ninety-degree nozzles that can be rotated though 360 degrees to suite any mounting situation. These blocks are rated to a generous 180W.
Installation was undoubtedly the simplest of the three kits on test, because of the self-contained design. The tubing connects using a simple fastening method that fixes and seals it without the need for any additional compression fittings. This means the tubing can be repeatedly connected without ever having to purchase single-use compression rings. The blue, textile-reinforced tubing is used as the feed from and return back to the main unit. For internal connections, Koolance supplies a length of clear tubing that was a touch on the tight side and quite difficult to fit. In fact, we used some hot water to soften the ends of the tube slightly before fitting it, rather than strain the blockâ€™s connectors by pushing too hard.
A good quality thermal compound is supplied in the kit and this is applied before the CPU block is attached. The black or blue retaining screw is then tightened until the ratchet kicks in, indicating the correct pressure. In fact, the only thing to pay attention to was making sure the screw is aligned up with the indent in the blockâ€™s load spreading plate below.
Filling the Exos was an unnecessarily messy process thanks to the small filler hole and pre-mixed coolant supplied in a large plastic pouch. Indeed we saw no valid reason for the filler hole to be so small, and the funnel in the kit wasnâ€™t a whole lot bigger either. Corsair probably has it about right with their Hydrocool unit. As for the pouch, well this is probably great for packing purposes but itâ€™s difficult to pour from and canâ€™t be resealed for later use. A bottle would be the better option.
Filling can also get messy because coolant returning to the reservoir does so with some force right below the filler hole. This can bubble up into the filler hole like a tiny geyser. For topping up you can just switch the unit off first, which of course means switching your PC off too, but for initial filling we prefer the pumps running and this mini â€œOld Faithfulâ€ just makes it harder to judge the level. Frustratingly we also found that a small pocket of air would form in the CPU block just half a centimetre or so above the outlet nozzle. Even after inverting the block several times to clear it, the air pocket kept returning. On the plus side, the Exos seemed to do a great job of priming and purging itself which is more than can be said for the WaterChill.
In use the Exos is possibly the noisiest kit on test, not helped by the fact that it relies on three 80mm fans rather than the 120mm units employed by the Cool River and Waterchill. This, plus the fact that itâ€™s designed to operate outside the case, and in most situations probably no more than a metre or so from your ear, makes it less suitable for those who see water cooling first and foremost as a route to near-silent operation. Thatâ€™s not to say itâ€™s horrendously loud, just that itâ€™s audible to a much greater extent than either of its two opponents in this roundup. When the fans are running full tilt the noise levels escalate to the point that they become intrusively audible and you really wouldnâ€™t want a situation where this was happening for any great length of time.
The lack of any kind of coolant level monitoring and visual flow confirmation are negative points considering how easily they could have been implemented. The latter could have been built into the front or side of the casing with little cost or effort, particularly as the return tube takes that route on its way round the radiator and back to the reservoir anyway. A simple post-purchase mod would certainly be worth the effort.