Zalman Reserator XT Hybrid Liquid Cooling System

by Greg King on March 14, 2008 in Cooling

Given their nature, external water-coolers have a lot of room to do things right. Zalman took full advantage of the space they had with the XT and delivered a superb external solution with excellent performance. Though slightly expensive, “you get what you pay for” rings true here.


A year ago February, we released our second review of a Zalman Reserator product. In that review, I was impressed with the Reserator 2’s ability to keep our E6600’s temperatures at a reasonable level all while operating virtually noise free. I was a bit turned off by the external nature of the unit but with its simplistic install process, this minor negative could be overlooked in my opinion.

Taking it back a bit further, Matt reviewed the original Reserator. His opinions of the original fell in line with mine for v2. While Matt took issue with the less than likable pump strength, the unit was able to keep his system temperatures at an acceptable level, and like the second version that I reviewed, did so at barely a whisper. Having cut our teeth on those first two coolers, when I caught wind of Zalman’s latest offering, the Reserator XT, with its active cooling approach, it’s safe to say that my attention was caught.

Meaning a combination of a reservoir and a radiator, Reserator is a name completely unique to Zalman. Quite literally, Zalman, not happy with Webster’s numerous offerings to the English language, set out to make their own word out of thin air much like I use words like craptacular and fantabulous to this day. Yeah, something like that I suppose.

Regardless, where Zalman has made their mark on the industry in the past has been through their silent cooling solutions. Both of the previous versions of the Reserator where completely silent thanks in part to their passively cooled designs but with the XT, Zalman has opted for better performance by including a rather large 140mm fan to actively cool the liquid by forced convection cooling.

As we dig deeper into the design of this unique cooler, we will see that Zalman put a considerable amount of time and energy into the engineering. But, were the changes make it worth the cost? Let’s find out.

Packaging, First Impressions

Our first experience with the Reserator XT on the bench was seeing the large box it came shipped in. The retail packaging of the Reserator XT is to the point and easily opened. Singing the praise of the Reserator XT, Zalman has included numerous selling point of the cooler on every side of the packaging but have done well in not going completely overboard.

Once opened, we start to get a good look at the included accessories that Zalman has bundled with the XT. Back from previous versions of the Reserator are the power supply jumper cable, PCI pass through bracket, tube clamps and anti-corrosion liquid additive. New to the XT though is an industrial-ish power connector that gets plugged into the back of the unit and is held in place by screwing in the jacket that surrounds the cord.

Also back, and for good reason, is a 12 foot length of PVC tubing and a small length of degassing tube with quick disconnects on either end. In past reviews the provided length of tubing has been more than enough so the addition of so much with the XT is a welcome site.

With any product, a trusty manual is provided as well. The manual can also be downloaded from Zalman’s site should you prefer your documentation in 1’s and 0’s form.

The final extra included with the Reserator XT is the CPU water block itself. Using the same overall design of the block included with the second Reserator, the newer ZM-WB5 water block removes the clear see-through top of the ZM-WB4 and uses a solid aluminum top that matches the color of the solid copper base. With a pair of barbs sticking out of the top of the block, the inlet should be the bard directly in the center of the ZM-WB5 and the outlet should be the other.

Turning the block over reveals a perfectly, and I mean perfectly, mirror polish that reflects the hose clamps quite well. This should provide the water block a solid contact with the heat spreader on our test CPU. The ZM-WB5 comes with universal mounting hardware so the Reserator XT can be used with any Intel 775 and AMD 754/939/940 motherboards.

Using a 12×12 pin grid, the ZM-WB5’s pure copper base should provide a good amount of heat transfer but with its copper materials, along with the copper piping inside the XT, use of a good anti-corrosion additive like the bottle Zalman includes is a necessity.

With a look at the basics out of the way, I’ll jump into a look at the physical unit next.