Zalman ZM500-HP (500W) and ZM600-HP (600W)
Products from Zalman have been tested in our lab regularly, receiving good reports from us. Like Thermaltake, this company began as a cooler maker, but it doesn’t hurry to produce super-powerful PSUs. It focuses on quiet operation instead. That’s why the 500W and 600W models presented here are the senior ones in the company’s product range although Zalman is planning to release an 850W model.
The ZM500-HP and ZM600-HP are built on the same platform, so I’ll be discussing them both together.
The PSU shows unmistakable traits of a product by FSP Group. It has a black matte case of a standard size and is cooled by a single 120mm fan.
The internal design is similar to the above-described FSP Epsilons except for two things: the card with connectors for detachable cables on the rear panel and the additional heatsink that is connected to the heatsink with diode packs by means of a heat pipe.
The ZM500-HP and ZM600-HP do not differ in their internal design.
The mentioned heatsink is near the external panel, under the vent grid, and the air that is being exhausted from the case is passing through that heatsink. This ensures enough airflow for the heatsink but the dense ribbing increases the aerodynamic resistance of the whole thing, thus reducing the amount of air that is being pumped through the PSU per minute.
You may worry that the air will flow around the heatsink, but it won’t. It is clear that the heatsink occupies most of the vent grid and is covered from above by the PSU fan. So, it will be cooled indeed and the only arguable question is how this additional heatsink affects the aerodynamic resistance and noisiness.