OCZ ZT Series 550W PSU Review

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OCZ ZT Series 550W PSU Review by VR-Zone.com

OCZ might have started off as a memory modules manufacturer but the company diversified into several other segments of the computer components market, such as CPU coolers, SSD drives and power supply units. OCZ has been marketing performance power supplies for over half a decade; however they turned into a major player after they acquired PC Power & Cooling, a company which specialized on the field. The company currently markets three series: The premium ZX series, the ZT series which are fully modular units aiming towards enthusiasts but are more sensibly priced than the premium ZX series and the value range ZS series. Today we are hosting the first power supply review of an OCZ product in VR-Zone and the product is no other than a ZT 550W power supply.

Manufacturer features and specifications

Single +12V rail for efficient power distribution
Heavy-duty protection circuitry
Fully Modular Cabling System
80-Plus Bronze Certified (85% efficient at typical load)
140mm ball-bearing fan
Dimensions: 150 x 86 x 175mm (W x L x H)
Rated at 45°C ambient
Premium 105°C electrolytic capacitors
Erp compliant, low power usage in standby mode
Active PFC
ATX 12V 2.2 Compliant
MTBF: 100,000 hours
5-year warranty

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OCZ supplies the ZT 550W power supply inside a sturdy, well designed cardboard box featuring a black-yellow theme. There is little artwork on the box and the theme revolves around a picture of the power supply itself and font art.



Inside the package the power supply is separated from the bundled items, which are inside a second cardboard box. The power supply comes wrapped inside a reusable nylon pouch.



The bundle that is supplied with the ZT 550 PSU is very simple and straightforward. Except from the black pouch which protects the PSU and the standard AC power cable you will only receive several short black cables ties, four typical 3M screws and a manual. There are no cable straps or any other special items.



You will also receive the modular cables necessary for the operation of the unit. The ATX, CPU and PCIe cables are common cables which have been sleeved, while the Molex and SATA power cables are ‘flat’, entirely black cables without any sleeving.

[siopao1984]

The ZT series power supply features an arresting design, with an all black body and striking yellow details. OCZ sprayed the ZT series power supply with a matte, non-reflective black paint. Measuring 175mm deep, the chassis of this power supply is slightly longer than typical ATX units but it is unlikely to cause any problems with the vast majority of computer cases.



Both sides of the power supply are covered by decorative stickers, featuring the company and series logos, as well as the unit’s power output inside a bright yellow frame.



The sticker with the unit's electrical specifications can be found at the top of the chassis and thus it will not be visible at all inside most cases.



The rear is entirely perforated to allow for the air pushed by the cooling fan to escape towards the outside of the case. The unit uses a standard AC power cable and there is an oversized rocker on/off switch next to it.



At the front side of the chassis one can find a few ventilation holes and the numerous connectors for the modular cables. This is a partially modular unit design with most cables still hardwired to the power supply. This unit offers the following number of connectors:



*Editor’s note: the floppy connector utilizes a Molex connector through an adapter.

[siopao1984]

The cooling of the OCZ ZT 550W unit is taken care of by a 140mm fan which is commonly found inside high quality power supplies. The fan is made by Yate Loon, a Taiwanese electronics manufacturer, and it is a ball bearing fan with a maximum rotational speed of 2800RPM.



The OEM behind the ZT 550W unit is Great Wall, a designer we first encountered when testing very high output power supplies. The same OEM is responsible for the premium class ZX series units.



The filtering stage of the ZT 550W unit is good, although not remarkable. It starts at the back of the A/C receptacle and continues on the PCB. It totally consists of four Y-type capacitors, two X-type capacitors and two ferrite coils. Strangely, the power supply does not have a surge arresting MOV, an omission which is very unlike OCZ.



The primary capacitor of the power supply sits next to an enclosed PFC choke and is supplied by Teapo and is rated at 420V/390μF at 105°C. Nippon Chemi-Con supplies the secondary side capacitors.



The heatsinks of the ZT 550W power supply are dense and of average size but should prove to be more than adequate considering the product’s efficiency and power output.

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In order to provide you with the most professional and accurate reviews, we are using the following equipment to test the performance of power supplies:

Modified SECC steel case with thermal generation and control components installed
Custom USB controlled DC load, 2.2KW maximum power drain
3KVA VARIAC
Lutron DW-6091 Power Analyzer
USB Instruments Stingray Oscilloscope
SL-5868P digital sound level meter
CompuLAB interface
MyPClab thermal interface
Labjack U3-HV interface
Custom calibration box
Custom software
More information about our testing equipment and methodology can be found in this article.



The OCZ ZT Series 550W unit successfully completed all of our tests without any operational and/or performance problems. The electrical performance of the power supply is great, with the voltage ripple barely reaching for 30mV with the power supply running at maximum load, although the voltage regulation is a little looser than most enthusiasts would expect.



The ZT 550W model manages to reach a very high efficiency of 88.6% under nominal load and it maintains a very high efficiency across the entire load range, although there is a significant drop of more than 3% when the power supply is heavily loaded.



Because of the high electrical efficiency and the strong cooling fan, the thermal performance of the ZT Series 550W unit is amongst the best we have ever encountered. The power supply barely reached a temperature delta of 16.7°C under maximum load.



It would seem that OCZ wanted to keep their unit running cool but not necessarily quiet. The ZT Series 550W power supply runs entirely silent but up to nominal load only; at 60% load the unit starts becoming audible and the noise rises geometrically as the load increases, ending up at a notably loud 45.8dB(A) under maximum load.

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Quality (30% of the total score)

The quality of the ZT Series 550W has left us with mixed feelings. On one hand we have a very well designed and made power supply, without any aesthetical or mechanical flaws and making use of great quality components from well known manufacturers, backed up by a lengthy 5-year warranty. However, the omission of a very basic and cheap to implement feature such as a surge suppressing MOV is inexcusable for a product of this class and did cost this power supply a few quality points.

Quality Score 8.5/10



Performance (40% of the total score)

When it comes to performance, the ZT Series 550W unit did well above average. The power supply delivers great electrical and thermal performance, reaching figures we rarely see here in VR-Zone. Conversely the efficiency and acoustics are tuned to peak while the power supply is under medium load, where any similar product should spend the vast majority of its operational hours, but degrade significantly when the unit is stressed. Still, we believe that enthusiasts will be more than pleased with the overall performance of the ZT Series 550W unit.

Performance Score 9.0/10



Value (20% of the total score)

Great price to performance ratio is perhaps the strongest feature of this power supply. At the time of this review, most stores retail this product at only 80$ USD (100$ SGD) which is a steal considering the features and performance this power supply offers. With such a price tag, the ZT Series 550W unit will certainly press extremely hard against the competition.

Value Score 10/10



Aesthetics (10% of the total score)

The OCZ ZT Series unit will definitely cover the aesthetic needs of every enthusiast, even those of the most hardcore of modders. The dark theme of the power supply is highly attractive and the fully modular design will assuredly make it a favorite among enthusiasts who are concerned about the aesthetic appeal of their systems. A slight complaint can be made about the striking yellow details, which can even drive a few modders away if the color does not match their systems or overall theme.

Aesthetics Score 9.5/10

[amary_17]

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taronga ug basa.

80$ USD (100$ SGD)

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