3R System Poseidon WCL-03Cu

Kit test – Joe

SUMMARY: Entry level kit with moderate performance.


The good guys at 3R System Co. were nice enough to send samples of the Poseidon WCL-03 90 & 120 Cu watercooling kits. There are two versions of this kit – the difference between them is the radiator – the WCL-90Cu features a 90mm fan and the WCL-120Cu a 120mm fan and larger radiator.


Key Features:

  • Magnetic Pump
  • Pump Head: 400 mm (16 inches)
  • Pump Flow Rate: 500 ml/min (about 8 gal/hr)
  • Radiator Material: Aluminum
  • Copper Base

Each kit features an integrated waterblock/pump arrangement:


Pic courtesy of 3R System

What looks like a fan is a magnetic flywheel which drives the impeller inside the waterblock. As you can see from the specs above, this is a very low flow system – about 8 gallons/hr (3R System spec); note also that the system’s head is minimal – 16 inches.

The waterblock’s base is not well finished:


I could feel polishing ridges very distinctly with my fingernail.

The radiator features a plenum on both sides


and tubes between.

Rad Front

The parts that ship with the kit


allows mounting options for AMD Socket A, AMD 64 and Intel P4 CPUs. Included with the kit is a rheostat for fan control. I found the low setting delivered 1884 for the 90 mm and 1350 rpm for the 120 mm fan; the high setting delivered 3219 for the 90 and 2300 rpm for the 120. I also found that the rheostat lowered rpms by about 8% compared to running without the rheostat at 12 volts.

I found fan noise at the lowest setting to be fairly quiet and busy at the highest setting – about 56 dBA at high (measured 8″ from the fan’s intake).

The Test

The WCLs were tested using the CPU Die Simulator. I tested with the rheostat set at its lowest and highest setting.


Die Temp

Ambient Temp



WCL-90Cu Fan High, 3219 rpm





WCL-90Cu Fan Low, 1884 rpm





WCL-120Cu High Fan, 2300 rpm





WCL-120Cu Low Fan, 1350 rpm





Delta = CPU temp – Ambient Temp
C/W = Delta / CPU Watts

Interpreting C/W: For every watt (CPUw) that the CPU
consumes, the HSF will limit the CPU’s temperature rise to (C/W x CPUw)
plus the temperature at the HSF’s fan inlet. For example, at an ambient temp of 25 C, a C/W of 0.25 with a CPU radiating 50 watts means that CPU temp will increase 50 x 0.25 = 12.5 C over ambient temp, or 37.5 C. The lower the C/W, the better.

Die Simulator results place the Poseidon WCL-03 90 & 120 Cu in the lower rank of watercooling kits tested to date (Heatsink Ranking).


The WCL 90 & 120 Cu kits tested about where I thought they would – OK for an entry level kit and OK for non-aggressive cooling. The 120 is marginally better, primarily due to the higher surface area of the 120 mm radiator. Both kits are compact and ship fully charged – no filling required.

What I found interesting is the difference a larger radiator makes – in this instance, about 2ºC. While this is not an apples-to-apples comparison (different fans), it does indicate that surface area matters – not a surprise to our readers.

Thanks again to 3R System Co. for sending these our way to check out.

Email Joe