Closer Examination

The Alphacool Eisblock XPX comes in a plastic wrap to help keep it clean out of the box, which is especially relevant in this polished nylon version. Yes, you read that right—the top is made out of nylon instead of the usual acrylic. Polished nylon, also harder to manufacture, is more resistant to cracking relative to acrylic, and this is the first CPU water block to make use of the material to the best of my (and also Alphacool's) knowledge. Compared to the metal frame over plastic that was used in the original blocks, the top is a single piece here, and the polishing is done well both inside and out, which makes for a detailed look of the coolant as it flows through, as well as any lighting you may want to add.

On top are two BSP G1/4" threaded ports with an Alphacool logo and "XPX Eisblock" printed underneath. The top design is also unique because of what Alphacool calls a ramp system they have patented to allow for increased and uniform coolant flow distribution over the microfins in the cooling engine itself. There is a parallel split at the outlet, which has the coolant move through with an arrested velocity at the edges. Alphacool claims this increases residence time of the coolant where it is needed, which should in turn help with heat transfer as well. We will be sure to test the block for flow and performance alike in this review.


Taking a look from the side, we can see exactly how thick the block is as a result of the relatively large top. Indeed, coming in at 65 x 65 x 30 mm, it is on the larger side of average, and this is even before any mounting bracket is installed. It does make for an impressive appearance combined with fittings, however, wherein even larger fittings seem right in place. In contrast to the original blocks which have an integrated LED that lights up the Alphacool logo and name on the top, there is no cable here to worry about unless you end up going with separately added lighting. Turning the block over, we see a large, transparent sticker with writing telling users to remove it prior to installation lest they inadvertently add a barrier against heat transfer. This sticker is used to protect the mirror finish given to the cold plate, which is very reflective. There is a slight convex bow to mate with a convex/flat CPU IHS, and the installation mechanism should provide for good contact in the center and all the way to the corners.


There is a notch in the top on all sides, just above the cold plate where the mounting bracket pieces slide in and mate with each other. As seen above with the Intel bracket, for example, it is a secure fit, but you will have to get around the initial inclination, so be delicate since you have to press the pieces against each other hard to get them to overlap and stay secured. Once done, it looks more like any other Intel CPU block (or AMD with the AMD bracket) as it comes out of the box. Alphacool has implemented this mounting-bracket design across their CPU block generations, and it has the added benefit of increased customization—more on that later.


Disassembly (done after all tests were complete, of course) is fairly easy—unscrew the four screws on the base plate and it comes apart. The cold plate is 3 mm thick, which is slightly more than most and decreases the rate of thermal transfer through it as a result of being thicker. The jetplate is metal (stainless steel from what I can see) and 0.3 mm thick—again fairly thick, it will provide for a noticeable bow all things remaining equal. The thicker cold plate will resist it, however. We get the usual machined set of ultra-thin microfins and microchannels which are ~0.2 mm thick. The microfins occupy an area of 32 x 34 mm, which is above average, and there are a lot of these, so all other things being equal, liquid flow restriction should be higher, but the increased surface area will aid with thermal transfer from the cold plate to the coolant.


Let's talk about that patented ramp system more. Coolant enters the designated inlet port and is moved towards the center and up a ramp. Then, the coolant is accelerated through a Venturi chamber which also splits up the flow before it is moved through the jetplate. Alphacool's intention here is to split flow up across a larger contact area on the microfins and microchannels; however, it is not convincing. For one, there is a mix of both coolant flow decrease and increase, and, secondly, even if the coolant is split up, it is still meeting the cold plate in the middle as with any other CPU block using a modern design. That said, there is an increase in the uniform distribution of coolant in terms of flow rate. Alphacool claims this will help produce more uniform and perhaps even above average performance at lower coolant flow rates (0.3-0.6 GPM).