CPU Water Pump Shootout

SUMMARY: Almost all small submersible water pumps can be effective in CPU water cooling systems if all components are on the same level; as the height increases, pumps that can maintain a pressure head at the specified distance are required.

I bought a bunch of small submersible water pumps to try out as part of a CPU water cooled system. I searched around different sites, comparing prices, warranties, sizes and pumping capacities. What follows is a comparison among various pump brands for two different types – magnetic drive and shaft drive.

The magnetic drive pumps have only one basic moving part – the rotor. It moves around a central fixed shaft driven by a pulsating magnet (the “motor”). The shaft drive units are driven by a motor spinning a shaft with an impeller at the end. The disadvantage of a shaft drive unit is that eventually the seal around the shaft will wear out and ruin the motor. The shaft in the mag drive units will eventually wear out and get noisy due to wobbling, but the “motor” itself should last a long time (no moving parts).

THE TEST

I used a stacked peltier to simulate a really hot CPU – something on the order of 100 watts. I have set up a portable water cooler that I use for testing motherboards (pic below) which uses a Perma-Cool radiator and Cool-Chip aluminum water block. Instead of the pump container pictured, I used a large pot so I could switch pumps using the same components.

I used the following pumps:

• Beckett G90AG – 90 gph @ 1′, 21 gph @ 4′
• Beckett G150APCP – 150 gph @ 1′
• Danner PondMaster 1.5 – 140 gph @ 1′
• OASE Aquarius 1 – 75 gph @ 1″, 30 @ 2.5′
• Reo 180 – 120 gph @ 1′
• Senfu Super – est. 130 gph

The OASE is carries a three year warranty, the Becketts two years and the rest one year. All the fittings take 3/8″ hose with the exception of the Senfu and Beckett G150 – I had to use a short piece of 1/2″ hose and insert the 3/8″ hose inside it – it was a snug and leak proof fit. Each pump was run until the peltier temps stabilized. I measured flow rates through the system using a quart container and extrapolated to gph.

CONCLUSIONS

In a relatively level system, just about any of these pumps will do the job. As height between components increases, the distance which the pump can move water becomes a deciding factor. In a mid-size case, the pumping distance is about one foot, assuming the radiator is at the same level as the pump (e.g – front of the case). If you plan to mount the pump at the bottom of the case with the radiator at the top, then something that will lift water at least three feet is a safe bet.

As to noise, I use a 120mm low noise intake fan, 92 mm exhaust and power supply fan; I am using the Beckett G90AG and can not hear it with the system running.

The Senfu continues to be a noticeably noisy pump; Senfu sent a new rotor for its larger pump which is much better than the original rotor but still noisy under load.

The most expensive of the lot is the G150, around $45. Prices range from $10 for the Reo 180 to about $33 for the Beckett G90AG, with most in the $20 range. Personally, I like a pump that has a longer warranty as I think that speaks to quality.

Note: I do not need all these pumps – if you want to buy the Beckett G150 ($35) or Reo 180 ($5), drop me a line. I did not pay for the Senfu, so I let’s have a contest: Tell us in 25 words or less why you deserve a free water pump (entries only accepted until Monday, 4/10/00, midnight). Decision of the judges is totally arbitrary.

Joe.