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The name IceGiant ProSiphon Elite might not be the first one that comes to mind when talking about high-performance CPU coolers made for the most extreme processors, but it soon could be. Located in Austin, Texas, J R Thermal A.K.A IceGiant, while not a new company, has started to focus their cooler expertise on the mainstream consumer market. Their revolutionary new cooler utilizes an already well established technology in a very new and creative way to solve the age-old problem of removing a huge amount of heat from a relatively small surface area. Join us as we take you on a tour of this new cooler and put it to the test with both Intel and AMD platforms. 

Specifications & Features

Their first product release is the ProSiphon Elite, which is a phase change process cooler. No, we are not talking about the power-hungry hybridized air conditioners used by the overclocking community and loosely referred to as ‘phase change coolers’. Rather, IceGiant leverages the process of liquid phase change, but the cooler requires no power to operate, other than the fans. It’s a liquid cooler with no moving parts, so how does it work exactly? The three fundamental steps of this cooler operation are as follows:

  1. Heat from the CPU boils liquid inside the evaporator – vapor flows up to the condenser
  2. Cool air flows through the condenser and liquifies the vapor
  3. Gravity drives the liquid back to the evaporator, and the cycle repeats

As part of the development process for this revolutionary new concept, J R Thermal built 30 prototype coolers for testing purposes. They then turned to industry professionals and cooling experts to help validate and test their new design. Out of that beta-testing process, they learned valuable lessons and ultimately changed the design to better fit the usage, thus the IceGiant ProSiphon Elite was born. They may be making their first steps into the mainstream consumer market, but that doesn’t mean they are inexperienced. 

IceGiant’s contract manufacturing partner has experience building millions of thermal modules with similar manufacturing processes as those needed for the ProSiphon Elite. IceGiant has worked closely with this partner for over 5 years, during which, more than 50 unique designs have been developed together. – IceGiant.

In terms of pricing, the ProSiphon Elite can be purchased directly on the IceGiant website for $169.99. While it may be at the upper end, that price point fits in nicely with the enthusiast aftermarket cooler market. It’s unknown at this time if there will be any new SKUs or when they will be available at US retailers. We did find a retail listing on and covering the EU markets.

Key Features

  • Excellent performance
    • Overcomes the physical limitations of air coolers
  • Extreme reliability
    • ProSiphon technology was originally developed to have zero maintenance in harsh environments
    • No pump = no moving parts to fail
    • No sludge buildup = consistent performance 
  • Safety
    • ​No water = no chance of water damage
    • Uses dielectric fluid, cannot harm equipment


Packaging & Product Tour

In terms of the retail packaging, IceGiant doesn’t disappoint! This behemoth of cooler ships safely in a very sturdy box. They took a different turn from the rest of the crowd in terms of the box style. You won’t find any super high-gloss pictures of the cooler on this box, instead, it’s a very simplistic flat black with a clean logo printed on the front. 

They even took the time to wrap up the box in plastic. This keeps the box in pristine condition during shipping, and also keeps it dry if the external sipping carton gets wet. On the backside of the box, they printed helpful facts and information about the cooler. 

A Closer Look

Out of the box, the ProSiphon Elite makes a great first impression. When holding this in hand, there’s no doubt that you are holding something very unique. Upon first inspection, we are struck by the design and colour scheme. It’s all-black except for two zinc-plated mounting screws and the blue-ish logo on top. There are two fans mounted on the cooler from the factory and also two more included in the box. 

The original prototype of this cooler contained two condenser cores. As you can see in the picture below, this official retail model contains three condenser cores. The liquid boils up and the vapor collects in the condenser cores where it cools down ultimately returns back to liquid. The tight grouping of fins cool the condenser cores, but from the looks of it, this design appears a bit air restrictive. 

The construction of the cooler and its parts is all aluminium. This material choice may be frowned upon in the computer cooling world, but there’s a caveat in this case. We’ve seen aluminium radiators in the past, but they have fallen out of favour due to the issues with open-loop custom coolers. Mixing materials such as copper, nickel, and aluminium is a recipe for disaster in terms of galvanic corrosion. However, due to the fact that the IceGiant is a completely closed-loop system, and there are no mixed materials, there is no possibility of corrosion or other related issues. 

The cooler is quite large, which should be a consideration when purchasing. Please refer to the diagram below for sizing information: 

  • Dimensions (with 2 fans): 251 x 164 x 104mm (W x H x D)
  • Dimensions (with 4 fans): 251 x 164 x 129.4mm (W x H x D)

Fans, Connectivity, & Accessories

The IceGiant ProSiphon Elite comes with a total of four 120mm PWM fans. Because the fin design appears restrictive, we’re happy to see that they included four fans so you can max out the airflow potential without needing to purchase fans separately. The fans contain piggyback wire harness connectors so you can drive both fans from one fan header, an excellent feature we are happy to see. 

  • Noise level: max. 32.2dB(A)
  • Fan speed: max. 2,300rpm
  • Connector: 4-pin PWM

In terms of socket capability, they’ve included everything you need for all major sockets on the market today. While it may not include support for legacy sockets such as LGA775, or obscure ones such as the FCLGA3647, we feel confident IceGiant coveres all the bases in terms of socket capabilities. 

  • Intel: 1200 / 115x / 1366 / 2011(-3) / 2066
  • AMD: AM4 / TR4 / sTRX4

Below mounting bracket assemblies for the platforms, we will be using: Intel LGA1200 and AMD sTRX4

Instead of re-inventing the wheel and trying to make their own thermal paste, IceGiant includes a small tube of Thermal Grizzly Kryonaut thermal paste, which is arguably one of the best on the market today. They also include accessories such as a fan splitter and a tool to make the installation easier.

In terms of orientation, you only have two options with this cooler. Because of the gravity-based phase change cycle, it’s designed to operate only in two directions. Those of you out there with 45 degree mounted motherboards should consider this cooler incompatible without further testing. 

Memory Compatibility

One of the biggest concerns with large air coolers is the memory height clearance. Due to its monstrous size, the memory height clearance is an even bigger consideration and factor with this cooler. We are happy to report that IceGiant has not overlooked this factor.

The memory height clearance is 48mm, which is more than enough to accommodate most memory modules on the market today. Out of at least 15 different kits of memory, the Team Group ARGB is the tallest we’ve ever tested. Although it’s an incredibly close fit with about 2mm of clearance, it does clear the cooler. This is the worst-case example and it passed the test!

Test Setup & Methodology

The procedure will consist of setting stable profiles in the bios and then running the stress tests for 30 minutes each time we make a change. While running the stress test, we will record the temperatures and noise levels to summarize later.

In an effort to be as thorough as possible, we wanted to test the ProSiphon Elite on both Intel and AMD. For the Intel platform, we chose the mainstream Z490 with i9-10900k. As for the AMD platform, we wanted to torture this cooler as much as possible, so we paired it with the incredible 64-core Threadripper 3990X processor. The testing process is as follows:

At the time of the idle/load measurement, the ambient temperature will be recorded with a Fluke K-Type probe, so we can exclude any variance in ambient temperatures. We will use the ambient temperature to arrive at the delta temperature.  The graphs will be the average Delta temperature of each test, which is to say the temperature above ambient.


When it comes down to the performance the Z490 platform results are up first. We compared the ProSiphon Elite against one of the best performing AIOs we’ve tested to date, the Corsair H115i RGB PRO XT AIO. Unfortunately, the IceGiant cooler couldn’t keep up with a top-performing closed-loop cooler. That’s not to say that it didn’t put up a good fight, because it did, please check out our results below. 

However, the story takes a different turn when it comes to the Threadripper results. We compared the ProSiphon Elite against the Noctua NH-U12S TR4-SP3, which is a robust 5 heat-pipe air cooler. The Noctua cooler was not able to handle the monstrous Threadripper 3990X once we started overclocking. But don’t worry, the ProSiphon Elite not only handled the overclocked Threadripper, but it blew away our expectations. 

Intel i9 – 10900k – Stock/Auto

Intel i9 – 10900k – 5100MHz @ 1.25V Overclock 

AMD Ryzen Threadripper 3990X – Stock/Auto

AMD Ryzen Threadripper 3990X – 3800 MHz @ 1.15V Overclock 

Sound Pressure


Maximum Overclocking

Due to the fact that the ProSiphon Elite did so well in the air-cooler battle, we decided to really punish with big CPU overclocks. Here we compare the IceGiant against a very large full custom water loop. At the heart of the system are two thick 360mm radiators with ultra-performance delta fans, and dual D5 pumps. In terms of the water block, it’s a Bykski CPU-RYZEN-X-MK. As water cooling goes, it’s an elite level loop easily capable of handling the 3990x.

Instead of testing stable overclocks with stress testing programs, we wanted to see the maximum overclock potential for benchmark programs. While the custom loop did technically win, the ProSiphon Elite came within 3°C, which is close enough to call it a tie based on experimental error. 

Here’s an example screenshot with the ProSiphon Elite cooler showing the idle and load temps. 


Overall we are happy very happy with the IceGiant ProSiphon Elite. It’s an unconventional type of cooler and it definitely fits in nicely within the enthusiast computer world. In terms of the physical characters, it’s definitely not for everyone.  With an all-black finish, it dominates the top-down motherboard view and doesn’t include any flashy RGB or other style elements. In a world dominated by RGB lighting and flashy designs, we can only conclude that the ProSiphon Elite it’s tailored to serious enthusiasts who are are not concerned about style. 

In terms of performance, the results are interesting and not exactly what we expected to see. Looking at the current Intel mainstream processor 10900K cooler comparisons, we were a little surprised that the ProSiphon Elite was a few notches below a top-performing AIO. To make things worse the noise level was a little on the high side compared to our AIO as well. However, the story took a big turn when we got out the Threadripper platform. Not only did it totally crush the Noctua, but it was effectively tied with our cull custom water loop. The thermal results are impressive on the Threadripper platform, to say the least.

We cannot explain exactly why the thermal performance is respectively better on Threadripper than it is against mainstream intel, but we do have a theory. The biggest difference between the two platforms is the IHS size and the core layout. Remember that Intel still uses a single die approach, meaning that all the heat created is focused to one central area on the CPU IHS which is fairly inefficient, whereas AMD’s chiplet design spreads out the core layout under the CPU IHS and effectively us able to spread heat created out to a winder overall surface area. We theorize that the cooling surface area of the CPU plays a big role in the effective cooling power of the ProSiphon Elite.

The ProSiphon Elite can be purchased directly on the IceGiant website for $169.99. Looking at the market for high-performance coolers it’s a bit on the high side. While it may be at the upper end, that price point fits in nicely with the enthusiast aftermarket cooler market. Those individuals who are looking for maximum thermal performance are often not pinching pennies looking for the cheapest price. The ProSiphon Elite is priced reasonably no matter what you intend to cool with it. However, if you plan on using this for a Threadripper build, then you are getting top-tier custom water cooling performance at AIO pricing. 


Excellent value / performanceIt's a big black box with no lighting or style embellishments
At 48 mm, the DDR4 memory height clearance will just about guarantee there are no issuesThe fans are loud when forced to run at 100% maximum speed
Impressive cooling potential, especially on Threadripper platforms Limited to a horizontal or vertical orientation (with respect to the motherboard)


As always, we want to extend our thanks to IceGiant Cooling for supplying us with this review sample. 


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This Post Has 3 Comments

  1. Nice work. An interesting teat would have been to take the fans off and see if it could passively cool the i9.

  2. The noise is higher in PWM mode according to your chart. The noise from this cooler is not competitive with the best options.

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