PolarFLO Universal CPU Water Block SF

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SUMMARY: Very good choice for CPU cooling, but not with low power waterpumps.


The good guys at PolarFLO.com was nice enough to send a PolarFLO Universal CPU Water Block SF to test. This is a LONG way from the first PolarFlo I saw that featured something like ¼” inlets.

The PolarFLO features:

  • Barb connectors for ½” ID tubing
  • 1 centered water inlet and 2 offset water outlets
  • Anodized or Plated 6061-T6 Aluminum top
  • Super flat and Super Finished 110 Copper base 0.000050 Flat and 0.5-1.0 RaMicroinch Surface Finish (0.0000005″ to 0.000001″)
  • Mounting screws, hose clamps and “Y” splitter

The use of two water outlets is interesting, but it does not yield higher flow through the system – the gating constraint is the smallest diameter opening used in the cooling loop.

If anything, the base is super shiny:


I can’t verify the flatness claim, but it is clearly extremely well finished – I agree with PolarFLO that any attempts to lap this base flatter would be unwise.


The PolarFLO was tested using the CPU Die Simulator and Waterblock Test Rig.


Test Conditions: Inlet Water Temp: 28.5 C; Mounting force: 15 pounds; Heat Load: 70 Watts.




Freeflow GPM

Waterblock GPM

Waterblock PSID






NOTE: These results are NOT comparable to tests done by others.
Unrounded data: 0.169 C/W with 0.0015 std dev.

Test Results indicate that the PolarFLO’s pressure drop (or head loss) across the waterblock is moderate; resistance such as this means that the PolarFLO should function well without using an unduly large waterpump.

For a comparison of the PolarFLO’s performance to other waterblocks tested to date, see Overclockers.com Waterblock Test Results.


The PolarFLO Waterblock is a very good choice for CPU cooling. In addition, with moderate flow resistance, the PolarFLO will perform very well with high power waterpumps, as long as other components do not unduly restrict waterflow.

Thanks again to PolarFLO.com for sending this our way.

Email Joe


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