Introduction

We would like to thank Coolermaster for supplying the review sample.

We didn't review Coolermaster's older GX Series, but from what we heard/read their performance was not very impressive. As it seems this forced Coolermaster to take a big decision and change the OEM (Original Equipment Manufacturer) from Seventeam to Enhance. Regardless the OEM change, in order to avoid confusion among the buyers, CM kept the same naming scheme adding only the “Bronze” word after the model name. So, for example, "GX-650W" became "GX-650 Bronze" and so on. Also, besides the upgraded efficiency all major characteristics like cable configuration and power specifications remained the same.

The updated GX series counts four models with capacities spanning from 450W to 750W, in 100W steps. In this review we will test the Cooler Master GX 650W Bronze, a unit that targets mainly upper-midrange systems. This PSU features a single +12V rail, uses a non modular cabling design and is equipped with a 120 mm fan which is provided by Adda, one of the best fan manufacturers. According to our sources the price of the GX-650W Bronze will remain at the same level with the older model, regardless all improvements. This is something very good of course for the end users.

Specifications

Warranty remained the same as on the previous model and it's pretty long for a PSU of this price range. Regarding the unit's protections, all but Over Current Protection (OCP) are present. In a single rail PSU with 52A at +12V OCP is not needed since, if there is a short then OCP's trigger point will be too high to avoid the melting of the wires. In single rail PSUs with mid-high wattage Over Power Protection (OPP) and UVP (Under Voltage Protection) keep the PSU safe if a short somehow happens. Finally, the maximum operating temperature of the PSU is only 40°C, according to CM, but we will crank up the temperature in the hot box up to 50°C and see how it goes.


The single +12V rail is very powerful since it is able to deliver up to 96% of the PSU's maximum rating capacity. This sounds a little weird because, as we will see in the internal's description, the PSU does not utilize DC-DC converters for the minor rails generation, so +12V circuitry shares many crucial components with the minor rails and if we take into account that the 5V&3.3V combined max power is 150W then 52A from +12V alone sounds very optimistic. During our second crossload test (CL2) things will clear out.

Cables & Connectors, Power Distribution

Cable length is sufficient but the distance among the connectors is too small. ATX spec recommends 150 mm and here we have only 100 mm. Also there are very few peripheral (4 pin Molex) connectors, a 650W unit should have at least 2-3 more. Finally all connectors use 18 AWG wires, the recommended size by ATX spec.

Since this PSU features a single +12V rail we do not have anything to comment about its power distribution.