Thermalright has certainly kept their eye on the ball lately, and they've scored yet again with their latest offering, the SP-94. This marks
Thermalright's ingress into heat-pipe technology, and they've made a distinguished entrance. The SP94 is an all copper thin-fin cooler, the embodiment of which centres around their SLK series. From what your about to see,
Thermalright has truly raised heat-sink manufacture, to an art form. Only recently
Thermalright introduced the SLK-947-U to market, and it improved significantly upon its predecessor the SLK-900U. The SLK-947-U, offered many small differences which all contributed to its success. The fins were slightly more elongated, and eschewed many of the right angles designed to separate each thin fin from the next.
While on the SLK-900U they seemed to be located at each angle on the plate edges which made up each fin, comparatively they inhibited air-flow. The SLK-947-U not only provided a more substantial base for a 92mm fan, but because it had less of the right-angles between each fin, its air-flow was improved. After its 92mm fan capability, astounding finish and aerodynamic qualities, perhaps the SLK-947-U's greatest attribute were changes made to the mounting hardware. From a prima facie perspective there were fewer pieces. And it was by far the most versatile to that point. With each successive design
Thermalright has improved this concept, culminating in the SP-94's solid one piece base
The SP-94 has taken ease of installation to its simplistic conclusion. The base of the cooler is machined from a solid block of pure copper. The four base extension mounts where the spring loaded screws drop through, are machined such that the underside accepts the tops of the standoffs. So the entire unit simply settles onto the four standoffs simultaneously. One simply lowers the unit onto the 4 stand-offs, drop in the screws and tighten a few turns for each screw moving perpendicularly among the screws. It's important to distribute the tension as you tighten them down. They simply tap out, so there are no worries about trying to match tensions. The design team at
Thermalright has achieved what I can only describe as "functional art," and its beauty definitely gives new meaning to the term "Performance Art."
Just when I thought
Thermalright had reached a pinnacle in heatsink design, they leap even further ahead. The SP-94 features all the attributes, and accoutrements of Thermaright's top SLK performer's, with the additional benefit of heat-pipe technology. First, I must say (and as the picture above shows) I have never seen a more finely lapped surface, mirror image is an understatement. This must have been wet-sanded down to 800-grit, and at least 600-grit. It's absolutely astounding. The construction is solid. It almost seems as if the cooler's been machined from a solid block of copper.
Prior to the release of the SP-94, when there just a few pre-production samples, people were criticizing the choice to use heat-pipe technology. In general they were concerned about mounting position. A few people had mentioned they thought the heatsink had to be mounted "upright" for the heat-pipe technology to work correctly. Well,
Thermalright has anticipated this scenario, and when the CPU is mounted onto the Abit IS7-E, or Abit IC7-G, (and from what I've seen from the trend) or on most Canterwood and Springdale boards, the pipes are located to take advantage of gravity. You don't get to be a leader in thermal management solutions, overlooking
prima facie issues, such as this. I therefore, decided to try mounting the cooler with the heatpipe-loops facing upwards (not suggested), and then with the loops facing down (suggested).
Phase-change, is a term which was placed on the lips of many PC-Enthusiast's by Chip-Con (now
nVentiv). Originating in Denmark they warmed the hearts of Overclockers the world over by freezing the heart's of their PC's, the CPU. The Prometeia, was, and still is a landmark in extreme thermal solutions.
Until Chip-Con's version of phase-change was made available to the masses, water cooling was as "cool" as it got. There were some LN2 experiments, but this was not feasible for most, and only lasting a few moments. Water cooling technology has certainly evolved to a reliable and safe alternative in its own right. Water-cooling, however; is still ultimately dependent upon forced air. One is still constrained by the room's ambient air temperature.
It's true that air blown over H20 results in better cooling by virtue of H20's ability to retain the kinetic energy/heat dissipating, and cooling the processor better than forced air itself. There are refrigerated water-cooled systems, and only in this situation will one actually obtain, and maintain substantially lower then ambient room/case temps. Along came Chip-Con, and exploited the reliability of refrigeration, and the extreme cooling potential of phase-change, The system uses a vacuum, which rapidly removes the phase-changed vapor, which nanoseconds ago, was chilled r134 refrigerant and is now the dissipated heat from the processor. This revolutionized cooling, because the resultant temp's maintained, even while overclocking, below freezing in most cases. The overclock’s achieved at such temps, are truly remarkable. The Heat-Pipe concept also uses the vaporization phase-change, albeit in a much more simplistic environment.
In heat-pipe cooling, copper tubing is filled with a liquid. The tubes are then built into an existing heat-sink design, or a design is built around them, regardless there's now the added benefit of phase-change. The process is implemented by means of allowing the lowest gravitational point of the tubing (where the water would naturally settle) to be incorporated into the base of the heatsink. The point where the processor's surface would be in closest proximity. The CPU's original kinetic energy (heat) conducts through the TIM, and then seeks the cooler heat-sink base, now infused with the heat-pipes. That heat is now conducted to the liquid within. Again the heat (kinetic energy) seeks the colder element, in this case the liquid. As that liquid now absorbs the kinetic energy, or heat (its molecules speed up) it expands and vaporizes. This vaporized liquid (or phase-changed (liquid > gas)) rises in the heat-pipes, taking with it the kinetic-energy (heat) from the processor. As the vapor rises in the pipes to the area where the fan is blowing air down, around, and over those pipes/fins, the gas within undergoes yet another phase-change. The kinetic energy is again released, from the gas, through the copper tubes, and the vapor then condenses to liquid form. As the liquid is cooled even further by the cold air being blown over the tubing, it begins its return to the base of the heat-pipes, via gravity, to begin the process all over again
Let's take a look at the SP-94 in detail and compare it to the older SLK-900U ->
