The most distinctive feature of the Z600 is that it's sold as a passive heatsink, which means it's delivered without a fan, although there is room to fit up to two of your own if you find it necessary.

If its tower design seems classic at first glance, it has two other rather unique aspects.

The first is that its heat-exchanging fins are arranged as a cross, rather than in a square, with the aim being to increase the surface area available to improve heat removal.

That's all well and good, but the result is a rather hefty heatsink that it's difficult to fit into an average computer case.

It was a struggle for us to cram it into an Antec Solo case, and even then the heatsink was in direct contact with the adjacent components immediately above it.

If there's not a lot of room on the inside of your tower, steer clear of this heatsink.

As we mentioned, it is possible to add your own fan to convert this into a forced air heatsink.

This is quite easy to do, as all you need to do is screw two plastic clips onto the side of the fan and then slot them onto the heatsink.

As with other passive heatsinks, we tried the Z600 out using a Noctua NF-U12P, a powerful fan that gives a good idea of what they're capable of with a fan attached.


Performance

We were pleasantly surprised by the cooling performances of this heatsink.

To start with, in passive mode (without a fan), it could control our quad core processor even beyond the temperatures recommended by the manufacturer: Cooler Master only claim that passive cooling is useful up to a thermal design power of 89W, but we used a processor which rated 105 for our tests without any problems.

Of course, this is only possible in a well-ventilated space, and preferably with a fan mounted near the heatsink to force out some of the hot air.

When we did add a fan, the Z600's cooling power was even more impressive, and it performed almost as well as the Noctua NH-U21P. 

A strong performance, yes, but bear in mind that it relies partly on the fan used.