Water Block Deconstructed
Courtesy of Alphacool
The Eisblock XPX CPU water block consists of four main parts, the aluminum top cover, the acetal top plate, the acetal mid-plate, and the nickle-plated copper base plate. The three inner pieces are sealed to one another by a series of rubber gaskets and four screws through the base plate. The aluminum top cover locks in place over the acetal sections, covering the LED and color plate. When assembled, the aluminum top cover and the acetal top plate form a flat plain for a water tight seal with the inlet and outlet barbs.
After removing the screws from the bottom plate, the water block can be separated into two distinct parts – the upper acetal pieces forming the inlet and outlet channels, and the copper base plate housing the micro-channels which sit directly over the surface of the processor's heat spreader and die assembly. The acetal mid-plate (bottom of upper assembly) seals to the copper base plate with a rubber gasket along the outside of its channel. It also houses the jet impingement plate directing water through the base plate's micro channels. Water is directed from the center of the micro-channels to the outlets on either side of the jet impingement plate.
The nickel-plated copper base plate contains a series of micro-channels through which the water is forced to cool the block's base plate (and the CPU in the process). The thin-finned nature of the micro-channels increases the surface contact area for the transfer of heat to the coolant. The inlet formed by the injection plate sits perpendicular to the water channels, forcing water across all channels and out via both sides of the base plate's micro-channels. The nickel plating helps minimize corrosion of the copper from contact with the coolant or air and gives it a degree of protection.
The only downside with using a micro-channel design is the increase in flow restriction inherent in its use – pressure builds up on the inlet side because water flow is restricted by the micro-channels. While the water velocity through the micro-channels is increased, the flow rate over the entire system decreases because of the micro-channels.
The upper part of the block can be separated into its component parts – the acetal top and middle plates. The top plate sits on top of the middle plate with the inlet and outlet channels sealed with rubber grommets forming the channels in the underside of the top plate.
The acetal top plate houses the inlet and outlet ports with channels in the underside of the plate. Both the inlet and outlet channels are shifted to optimize coolant flow through the base plate micro-channels. The inlet channel redirects the coolant from the side to the middle of the block. The outlet channel collects coolant from the two dump points on either side of the base plate and reforms it into a single stream through the outlet port.
The top of the middle acetal plate has identifying text for the inlet and outlet ports, visible if light is shown through the ports with the block assembled. The design of the inlet channel creates turbulence as the water enters the block but prior to it going through the jet impingement plate. The incoming stream is forced to split and reform, accelerating the coolant stream prior to it passing through the impingement plate.
The bottom of the middle acetal plate houses the jet impingement plate that forces the coolant through the base plate micro-channels. The inlet channel seals to the impingement plate with a rubber grommet. Further, it contains a plastic insert that encourages the incoming stream to spread across the entire length of the impingement plate rather than hitting the center of the plate directly and spreading. The dual outlet ports, to the top and bottom of the impingement channel, are centered in cavities used to collect the coolant after passing through the copper base plate's micro-channels.