[nextpage title=”Introduction”]

With the computer parts consuming more and more power, choosing the correct power supply for your system is very important. A wrong power supply can make your computer freeze, crash, reset from out of the blue and overheat (because the power supply has an ultimate role in the airflow inside the PC – a lot of people aren’t aware of this).

OCZ has two high-performance power supply series, PowerStream and ModStream. PowerStream series offers 420-, 520- and 600 W models and has overvoltage trimpots, a feature for die-hard overclockers. ModStream, on the other hand, offers 450- and 520 W models (with 550 W and 620 W peak loads, respectively) and doesn’t offer overvoltage configuration, however this series has a modular cabling system, where you plug on the power supply just the cable you will really need. Removing unnecessary cables from inside the computer helps a lot the airflow inside your PC. Another difference between these two series is the size and location of the power supply fan. PowerStream series uses a regular 80 mm fan located on the back of the power supply, while ModStream series uses a 120 mm fan located on the bottom of the power supply.

OCZ ModStream 520 W Power SupplyFigure 1: OCZ ModStream 520 W power supply box.

In Figure 2, you can see ModStream 520 W from OCZ. Usually the power supply fan is located on the back of the power supply. On this power supply, the fan is located on its bottom (on the picture the power supply is upside down), while its back is almost completely opened, protected by a grill. This allows a better airflow. Also this power supply uses a big 120 mm fan, which is more silent than 80 mm fans. This fan is transparent with blue LEDs that lights the fan when you turn on your system.

OCZ ModStream 520 W Power SupplyFigure 2: OCZ ModStream 520 W power supply.

On the front of the power supply you will find the connectors for the modular cabling system. As we mentioned, you need to install only the cables you will actually need, so no loose cables inside the computer case blocking the airflow.

OCZ ModStream 520 W Power SupplyFigure 3: OCZ ModStream 520 W power supply, front view.

A piece of advice: as you can see, there are two six-pin squared connectors with different colors (one is light blue, used by PCI Express video cards auxiliary power, and the other one is light blue, used by Serial ATA hard drives). Pay close attention when using this connector. When we installed this power supply we mixed this connection and installed the auxiliary power from our video card (dark blue) on the connector targeted to Serial ATA power (light blue). It took us a while to figure out why our computer wasn’t turning on.

[nextpage title=”Cabling System”]

In Figure 4, you can see the cables that come with the power supply. The cables are UV sensitive, so if you install an UV light inside your case the cables will glow. As you can see, this power supply comes with 10 wire holders, five Velcro holders (which means that they are reusable) and five thin plastic holders. With these holders you can organize the cables inside your PC, improving the airflow.

OCZ ModStream 520 W Power SupplyFigure 4: Cable and cable holders that come with OCZ ModStream power supply.

The motherboard power plug used on this power supply is really interesting: it fits both 20-pin and 24-pin motherboards without using an adapter. Its 24-pin plug can be transformed into a 20-pin plug by detaching the extra wires, which is very easily done, as we show on Figures 5, 6 and 7.

OCZ ModStream 520 W Power SupplyFigure 5: The motherboard power plug can fit both 24-pin and 20-pin motherboards.

OCZ ModStream 520 W Power SupplyFigure 6: Sliding the extra pins to transform the 24-pin plug into a 20-pin plug.

OCZ ModStream 520 W Power SupplyFigure 7: Now the power plug fits a 20-pin motherboard.

The auxiliary power cable used by PCI Express video cards has an extra filtering feature, as you can see in Figure 8 (we cut the light blue plastic protection to show you the components). Two electrolytic capacitors, two ceramic capacitors and one ferrite tube are used to make this filtering circuit.

OCZ ModStream 520 W Power SupplyFigure 8: Extra filtering on the PCI Express video card auxiliary power cable.

[nextpage title=”A Look Inside The the Power Supply”]

Since we are very curious, we decide to open the power supply to take a look inside it.

The first thing we discovered was that this power supply is manufactured by Topower.

OCZ ModStream 520 W Power SupplyFigure 9: Inside OCZ ModStream 520 W power supply.

OCZ ModStream 520 W Power SupplyFigure 10: Inside OCZ ModStream 520 W power supply.

For a layman, it looks like any other power supply. But if you pay really attention you will see that OCZ uses better quality components inside their power supply, like transistors that can really deliver the current claimed by the manufacturer, better heatsink for the transistors, better electrolytic capacitors with higher capacitance and a lot of extra filtering to ensure very stable voltage outputs with no spikes or noise. In Figure 11 you see part of the input line filter, which "generic" power supplies simply don’t have.

OCZ ModStream 520 W Power SupplyFigure 11: Input line filter.

[nextpage title=”Main Specifications”]

In Figure 12 you can check the power supply label, which has all its specs for both 450 W and 520 W models.

OCZ ModStream 520 W Power SupplyFigure 12: OCZ ModStream power supplies specs.

As for its price, on Pricewatch we could find the 450 W model being sold between USD 75 and USD 87 (average of USD 81) while the 520 W model was being sold between USD 89 and USD 94 (USD 91.50).

[nextpage title=”Conclusions”]

High-performance power supplies are not only required by gamers with high-end video cards. Even regular users with mid-range video cards and high-performance processors need to consider buying a better power supply.

We found ModStream power supply from OCZ a terrific product. If you are looking for a high-performance power supply, go for it. Its modular cabling system and the Velcro cable holders are awesome for organizing the cables inside the PC, thus providing a better airflow inside the PC case. Also, the position and size of the fan (on the bottom of the power supply, not on its back) added with the fact that the back of this power supply is completely opened makes it a terrific cooling device for your PC. In these days where overheating is a really common problem, this is particular important to note.

Another important detail is that it is cheaper than its sister series PowerStream. Actually PowerStream series, which has trimpots for overvoltage adjustments, is targeted to serious overclockers. If you are not that crazy of changing the voltages of your power supply but still want a high-performance and stable power supply with terrific cooling, ModStream is the way to go.

Also, OCZ gives a three-year warranty for this PSU. This shows the commitment of this company with the stability and quality of their power supplies.