Global Win Jefi Watercooling Kit

Kit test – Joe

SUMMARY: One of the more interesting watercooling kits – OK performance.


The good guys at Global Win were nice enough to send the Jefi watercooling kit for a test spin. This is a very innovative watercooling kit – one that the “bong” watercoolers in our audience will appreciate.

Key features include:

  • Mounts for Intel P4 Prescott, Intel P4-478, AMD Athlon 64 XP3400+, AMD Athlon XP 3200+ CPU
  • Glass reservoir
  • 3 watt 120 volts waterpump, rated 180 lph
  • Temperature controlled fan 2000 – 4000 rpm, 27 to 55 cfm, 20 – 41 dBA

The reservoir included in the kit is made of glass:


The fan (temperature controlled) assembly features a number of “pegs”:



The fan assembly sits on top of the reservoir:


Once filled with water, there is a floating aluminum ring unit:


The aluminum ring sits on the plastic floating donut:



And here is where the evaporative cooling takes place. Water circulates around the fan unit and drips down the pegs underneath the fan:


The aluminum ring spreads water over a large surface area; the fan directs air over the aluminum ring, evaporating water – hence this is a very compact evaporative watercooler.

The waterblock is an aluminum body with a copper base:


The copper base is adequately finished:


There were no gross finishing marks or ridges, although a good lapping will increase performance a bit. The mounting clips are great – they center mounting pressure over the center of the CPU core, where it should be.

The waterpump is rated at


3 watts, 120 volts, with a flow rate of 180 lph. There is a rheostat


included with the kit as well. The parts that ship with the kit


include Socket A and P4 mounts and a glass thermometer to mount inside the reservoir.


The Jefi was tested on the CPU Die Simulator which gives results that are unaffected by motherboard influences.

Fan noise was very low, as were rpms. Pump noise was minimal – if you listened real hard, you could hear a slight hum close up. The only other sound was a very slight dripping noise. Overall, under normal use, this is a low-noise system.


Die Temp
Ambient Temp
49.3 C
25.4 C
23.9 C

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 Jefi in the md-lower rank of watercooling kits tested to date (Heatsink Ranking).


Global Win’s Jefi is an interesting choice for Socket A cooling, although this kit will require more attention by users than a self-contained system. There’s more here than meets the eye, and I wonder if some mods could make this an even better performer than what you see here (accepting that the fan may be defective). For example, if this kit is used on an aquarium, the larger volume of water will increase performance.

For low-noise cooling, the Jefi is an OK choice, although users must accept that this is an evaporative cooler – this means that under very dry conditions, the reservoir may need frequent filling. 24/7 unattended operation is not an option.

Overall, I think this kit could be an interesting way to explore the evaporative cooling world. Performance is OK for low noise, non-aggressive CPU cooling.

Thanks again to Global Win for sending this our way.

Email Joe