Overclock Labs ® Block

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Waterblock Test – Joe

SUMMARY: Good choice for CPU cooling with moderate power waterpumps.

OC Labs

Nikolaos Kavvadias over at OC Labs was nice enough to send their Overclock Labs® Block waterblock to test. OC Labs is a new face on the scene and is headquartered in Italy (Bel Paese).

Overclock Labs® Block features

  • Chrome-plated barb connectors for ½” ID tubing
  • All copper construction
  • Mounting for both P4 and Socket A systems

The block is milled from a solid copper block – it weighs a hefty 360 grams, measuring 2″ x 2″ x ¾” (ex fittings). Based on pics at OC Lab’s website, it appears to be a cross drilled type. The dimple you see between the fittings is for the mounting hardware:


The base of the screw is tapered to fit into the dimple – idiot proof. This system I think is the best – it centers mounting pressure directly over the center of the CPU core, for either P4 or Socket A mounting. With center mounting, there is no risk of exerting too much force on one side, thereby compromising performance. Note there is slight assembly required.

The base


shows polishing marks but is not apparent to the touch; there are also polishing marks apparent on other surfaces.


The Overclock Labs® Block 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.



Pressure Drop – psi

Pressure Drop – inches H2O

OC Labs




NOTE: These results are NOT comparable to tests done by others.
Unrounded data: 0.163 C/W with 0.0010 std dev.

Test Results indicate that the Overclock Labs® Block’s pressure drop (or head loss) across the waterblock is moderate; resistance such as this means that Overclock Labs® Block may need a moderate to large waterpump to extract maximum performance, especially if other components in the system are restrictive.

However, I found that performance degraded by only about 0.4ºC with at a flow rate of 0.5 gpm and improved by about 0.3ºC at 1.5 gpm – very “even” results and somewhat less than some other waterblocks tested to date.

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


Overclock Labs® Block is a good choice for CPU cooling. With moderate flow resistance, the Overclock Labs® Block needs a moderate to high power waterpump to shine, depending on the resistance of other components in the system. The mounting system is a plus – one pressure point centered over the CPU core is much preferred.

Thanks again to OC Labs for sending this our way.

Email Joe


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