Waterblock Test – Joe
SUMMARY: Very good choice for CPU cooling with moderate-high power waterpumps.

The good guys at Viscool were nice enough to send their CPU V2 Waterblock waterblock to test.
The Viscool CPU V2 features
- 5mm copper base with aluminium top
- Nickel steel fittings with outside diameter of 10mm, on request 12mm, thread: G1/4, Screw connector AG 1/4′ on 10/8mm
- Waterblock mounting adaptable to all current CPUs
The copper base features an interesting design:

You will notice below that the Viscool CPU V2’s pressure drop is fairly high – this is due to its interior design.
The base is well finished; I used the Poor Man’s Flatness Test on it with good results:

Rotating the base 90º:

This view is more difficult to see as the polishing marks are circular.
Mounting involves fixing four brackets to the top of the waterblock:

You can orient the brackets to fit just about any configuration. Included with the waterblock is the mounting hardware:

The Viscool CPU V2 was tested using the CPU Die Simulator and Waterblock Test Rig.

Waterblock | C/W | Pressure Drop – psi | Pressure Drop – inches H2O |
Viscool CPU V2 | 0.13 | 1.39 | 38.5 |
Unrounded data: 0.129 C/W with .001 std dev.
Test Results indicate that the Viscool CPU V2’s pressure drop (or head loss) across the waterblock is moderately high; flow resistance such as this means that Viscool CPU V2 will require a good waterpump – anything less than 300 gph might compromise results, depending upon how restrictive other components are in system.
I found that reducing flow to 0.5 gpm resulted in a performance decrease of about 0.7ºC and increasing flow to 1.3 gpm resulted in a gain of about 0.4ºC.
For a comparison of the Viscool CPU V2’s performance to other waterblocks tested to date, see Overclockers.com Waterblock Test Results.
Viscool’s CPU V2 Waterblock is a very good choice for CPU cooling; the Viscool CPU V2 should perform well with moderate-high power waterpumps (300 gph or more), as long as other components do not unduly restrict waterflow.
Thanks again to Viscool for sending this our way.
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