Introduction

We would like to thank OCZ for supplying the ZS 650 W review sample.

OCZ is trying to make a dynamic re-entry in the PSU market with the affordable and value oriented ZS Series. In the last review we reviewed the ZS 750W and concluded that its price needs an urgent revision in order to avoid the hard competition it has to face in the $100 category from other PSUs that utilize newer platforms and in general perform better. The ZS 650W costs only $10 less than its bigger brother so it will also face strong competition, especially since it uses the same outdated platform. Nevertheless, before we draw any conclusions let's first finish all tests and then conclude if the price/performance ratio will work out on today's market.

The ZS series may be positioned below the ZX models, performance and price wise, however it uses all Japanese capacitors contrary to the ZX units, which utilize Teapo ones. That's quite surprising and it's the first time we see a "weaker" series utilizing better caps than the high-end models! Regarding the rest of features, the ZS 650W is 80 PLUS Bronze certified, it uses a non-modular cabling design and is equipped with two PCIe connectors.

Specifications

The PSU's continuous output power is rated only up to 40°C so we will have to test it at lower than 50°C to avoid dramatic situations, since Over Temperature Protection (OTP) is absent. The warranty is three years, a decent period for a PSU of this price tag, however Corsair in the similar priced TX 650 V2 offers five years. The price is a little higher than we expected and renders the unit more expensive even compared to the aforementioned Corsair TX 650 V2 which uses a newer platform. At the time of the review there was a very good deal for the ZS 650W with a $25 mail in rebate which lowers the price to $64.99. A very good deal for an 650W branded PSU, but as you already know, mail-in rebates are not permanently active so we have to judge the unit according to its official price.


There is only one +12V rail which can deliver about 100W less than the unit's max capacity, something highly expected since the PSU does not utilize DC-DC converters for the minor rails generation.

Cables & Connectors, Power Distribution

All cables are quite long, except for the 24 pin ATX cable. There two PCIe connectors and strangely only one of them is 6+2 pin. Normally both should have 6+2 pins and not only one of them. Also as you can see from the table above, the PSU isn't equipped with FDD connectors, neither peripheral to FDD adaptors. Either way this isn't a big loss since nowadays floppy disk drives have disappeared. What troubled us the most regarding the cabling design of ZS 650W is the very short distance among SATA and peripheral connectors, which is way shorter than the recommended by ATX spec length (150 mm). Also OCZ did not bother to sleeve the wires between SATA and peripheral connectors.
All connectors use 18 AWG wires, which is the recommended by ATX gauge.

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

Packaging

The packaging is exactly the same as the OCZ ZS 750W. Actually only the capacity description changes. On the face of the box there is a photo of the unit on a black background along with a very brief description of its characteristics. On the rear side you will find a reference to the PSU's highlights and on the top and bottom sides additional information is given regarding technical characteristics, power specifications and connectors description.