![[H]ardOCP](/images/blank.gif){kind=small}
- Date:
- Thursday , October 08, 2009
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
OCZ Z Series: Z850M 850W Power Supply Review
Today we see what OCZ means when it says, "True to our enthusiast roots..." OCZ claims ultra-high efficiency and has gotten an 80plus.org Gold Certification. The 850 watt realm has proved elusive for great power supplies. Now to see if this PSU can garner an [H] "certification?"
Build Quality
As we already know the OCZ Z850M feature a single 135mm fan design that is used in the same vein as 120mm fans in that they can provide for quiet cooling environments due to the ability to move a larger volume of air at slower speeds than a smaller diameter fan. The 135mm fan is just short of the largest diameter fan we are likely to see in ATX power supplies given the physical constraints of the form factor. While great for quiet computing environments the key criteria in our evaluation is whether or not the cooling solution is sufficient, not necessarily it’s sound output level or form factor, although we certainly listen for offending units.
External Build Quality
The external build quality of the OCZ Z850M is excellent. The unit comes trimmed out in a shiny brushed metal finish that looks rather striking. Along with this we find the large sticker and 80Plus Gold label on the unit. Interestingly, we also see the first mention of the "Fan Delay-Off Function" here as well. Why this feature isn’t advertised anywhere else is unknown, but the purpose of this feature is to keep the fan running after the unit shuts down in order to continue to cool the unit and prevent damage to it which is a great feature addition. Moving on, the front of the unit is dominated by the color coordinated modular interface and the rear of the unit is clear save the AC receptacle and on/off rocker switch. Lastly, from the top we see the lone 135mm fan dominates the unit and is embossed with the OCZ logo.
The OCZ Z850M is ~6 1/4 inches long and the cables all reach out to ~21 inches at the first or only connector with the sleeving being complete and well done on all of cables.
Internal Build Quality
Once we pop the top of the OCZ Z850M we find a seemingly well put together power supply. The unit is dominated by the three large golden colored heatsinks in what looks to be a fairly traditional power supply layout. All of the heatsinks have places for more power components and the PCB is screened for more power components across the board. This is most likely due to the fact that this PCB is designed to be used in units up to 1200W and does not represent any corner cutting in this case. The fan paired with those heatsinks is a Globe Fan rated at 0.33A at 12v. Lastly, the soldering on this unit is generally well down across the board with just one interesting section where we find a bus bar soldered over to increase the current carrying capacity, but this was done well enough compared to other units we have seen (Tagan BZ1300) that have employed such things.
As we swing over to the primary side, we see the far outside heatsink houses the APFC power components while the APFC coil is situated near the modular interface. Just in front of that we find the main filtering capacitors which are fitted into a cutout of the heatsink and are provided by Rubycon. The pair of Rubycon primaries are rated at 400v 330uF 85C. Interestingly, the primary design on this unit seems to be your run of the mill double forward configuration (it will be interesting to see if this is capable of those 80Plus Gold numbers that it advertises so prominently).
Over on the secondary side we see the beginning of the input filtering housed on the AC receptacle and then finished on the main PCB trailing towards the primary side. Underneath the largest heastink in the unit, we see that there is a single large toroid coil and an add-in PCB indicating that the minor voltages are derived from the 12v rail in this unit. This is a large part of the reason that this unit could possibly qualify for 80Plus Gold certification as DC-DC designs typically are more efficient than the older independently regulated designs found on high end units. In addition to this, we see another PCB here that houses the OCP/OVP and other protection circuitry along with the fan controller. In between these two PCB’s, and under the wiring, we find that this unit is populated by a mix of standard and solid capacitors from Nippon Chemi-con. The wiring above these capacitors is well bundled and routed out of the unit through sleeving that comes all the way into the housing and through a wire guard. The modular PCB is well constructed and the wiring to it is well routed as well leaving us with no real complaints. Lastly, if we look back at the main PCB we can see that this unit was originally designed as a 4 12v rail unit by the OEM.
Build Quality Summary
The overall build quality of the OCZ Z850M looks high. The satiny yet slightly shiny brushed metal finish on the unit really is quite attractive and the unit is seemingly well put together externally. The fixed cables are well sleeved, as are the modular ones, and the modular interface has a map placed under it so users know which cables go where. The interior of the unit is also well put together and the landscape is dominated by three large well machined aluminum heatsinks. The secondary features a DC-DC VRM design that derives the 5v/3.3v rails from the main 12v and is situated on an add-in PCB. The wiring on the secondary is generally neatly kept and routed to either the modular PCB or out of the unit through a wire guard. The component selection is top notch as the primary capacitors are Rubycon made and the secondary is filled with Nippon Chemi-con capacitors. All in all the unit seems to be very solidly built so let’s move on to see how it performs.