Cooler Master has been working in the cooling systems sphere for 10 years already, and its products meet the needs of the most hypercritical users throughout the USA and Europe. Cooler Master has quite strong positions even in Japan where consumers are not indifferent to coolers and other hardware stuff from their childhood. A secret of success of this company is simple: its business is built on the proper concern for quality of its products, a careful selection of components, a fine approach to development and construction of all standard and exclusive models of processor coolers which are proved by the production certification according to the ISO 9001 standard.

And today we are going to examine new coolers from this company which are DP5-6H51, DP5-6I11A, DP5-6I31A and DP5-6I31C-A1.

General impression

Let's start from the DP5-6H51. This model has an aluminum heatsink of 60x60x35 mm with average fin parameters (1.2 mm wide, 28 mm high, 2mm step, and a console factor of 14) and a standard fan of 60x60x15 mm.

But its ordinary appearance hides several interesting peculiarities.

First of all, the fan is placed on a frame made from soft plastic which is attached to exterior heatsink fins. As a result, the fan doesn't touch the heatsink, and the plastic frame works as a vibration damper, thus, lowering strength of structural noise.

Secondly, the BS601512H fan produced by Bi-Sonic Technology Corp. has quite a low impeller speed - about 4500 rpm, but its performance is rather high (22 CFM). Besides, this fan (together with the DP5-6H51 heatsink) has a low noise level whose spectral distribution is very "friendly" to a human ear (sound pressure levels in octave parts of 500, 1000 and 2000 Hz are not very high and almost equal).

At last, the heatsink's base is excellently polished and almost ideally flat; therefore, quality of the thermal contact with a processor core is quite high.

Moreover, the Dow Corning 340 thermo glue these coolers are covered with is rather efficient.

An installation of this cooler must pass without a hitch on the most of modern Socket 370 and Socket A of mainboards. The dimensions of the DP5-6H51 model meet the AMD's requirements for average Socket A coolers, that is why I don't think there will be any compatibility problems. A mount of the cooler is convenient: the hold-down pressure is not more than 1.5 kg/cm2, and an installation process becomes easy and safe.

And now we are moving to the high models of the Cooler Master DP5 series - DP5-6I11A and DP5-6I31A. They consist of an aluminum heatsink of 60x60x40 mm with rather good fin parameters (1 mm wide, 1.6mm step, central fins are 32 mm high and a console factor is 20) and fans of 60x60x10 mm and 60x60x15 mm.

The DP5-6I31A cooler carries a Delta AFB0612VHC fan which is of super quality and has a good performance (28 CFM). Despite a relatively high rotational speed (5300 rpm) and two frictionless bearings its noise level doesn't overstep the specified limits because of the optimal geometrical design of the fan and a well-balanced impeller.

The DP5-6I11A cooler has a simpler fan, it is BS601012H model produced by Bi-Sonic Technology. But its quality is also excellent. Besides, although its maximum performance is lower (24 CFM), the thermal effectiveness doesn't yield to that of the DP5-6I31A cooler.

The only shortcoming of these models is Chomerics T725 interface instead whose thermal efficiency is far not perfect. That is why you'd better remove this interface, clean the heatsink's base carefully and then use normal grease.

The installation procedure of the DP5-6I11A and DP5-6I31A coolers is identical to that of the DP5-6H51, as all of them have the same mount and the same dimensions of the heatsink's base.

And now comes the chief model in this series - DP5-6I31C-A1.

It differs from the DP5-6I31A in dimensions of the heatsink (80x60x40 mm against 60x60x40 mm; the fin parameters are the same). Therefore, a larger heat exchange surface must provide a better thermal efficiency of the cooler if the heatsink is ventilated good enough.

In our tests the DP5-6I31C-A1 outscores the DP5-6I31A by 3°C. This is a quite interesting result as the Delta AFB0612VHC fan is rather weak for full-size heatsinks. But the DP5-6I31C-A1 has a better thermal efficiency because of an optimal step-like design of the heatsink (fins are lower on the edges than in the center); such a design allows decreasing air resistance of the heatsink and using an air flow the most optimal way. In case of fans with not a high static pressure (Delta AFB0612VHC) a positive effect must be close to the maximum one, and the DP5-6I31C-A1 demonstrates it.

On the other hand, such a large heatsink may cause problems in course of installation. They are lacking on the Socket A from brand-name manufacturers, but like in case of Volcano 5/6Cu/6Cu+, budget Socket A or Socket 370 boards may have some compatibility problems.

Tests

Let's start with stress tests. All models have passed them almost flawlessly. The Bi-Sonic BS601012H and BS601512H fans worked stably both at increased and decreased power supply without much heat-up or vibration. The Delta AFB0612VHC coped with non-rated modes but it heat up a bit more at the increased power supply. All three models managed to stand a long shutdown of the impeller: during 24 hours they didn't heat up much, and after the testing the fans ran stably.

Besides, the quality of the bearings was perfect, a bearing-shaft gap was normal, and the quality of the grease and of mounting was very good.

And now let's move to the temperature results (for the theory see Coolers Comparison Technique). The test system configuration remains the same:

• ASUS CUV4X-E mainboard, rev. 1.05
• Intel Pentium III 1 GHz processor (overclocked to 1.125 GHz)
• Windows 2000 Professional Service Pack 2

We use the CPUBurn utilities for processor overclocking and the MBProbe 1.30 one for temperature control.

Temperature measurements

Notes: AlSil-3 grease was used as a thermo interface
The diagram shows an integrated result

And here are noise characteristics.

Note: The background noise level is 25 dBa

Conclusion

All the models of the Cooler Master series have shown excellent quality and good thermal efficiency. Among their advantages are:

• easy installation/deinstallation
• good compatibility with the majority of advanced Socket A and Socket 370 mainboards
• high quality and reliability of the fans
• acceptable noise level
• attractive price

On the other hand, the higher models have quite bad thermal interface and weak compatibility of the DP5-6I31C-A1 with budget Socket 370 and Socket A mainboards. But these drawbacks are not grave.

The Cooler Master DP5-6H51, DP5-6I11A and DP5-6I31A coolers can become an excellent purchase for owners of Socket A/370 processors up to 1.33 GHz. And the Cooler Master DP5-6I31C-A1 model which has the best price/quality ratio can be recommended even for the "hottest" Socket A processors (Athlon XP 1533 MHz and higher).

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