A thousand watts, a kilowatt. A kilowatt or a thousand watts. We can't decide which term sounds larger when spoken aloud. In any case, when said aloud, both terms are conversation starters when in discussion about PC power supplies. In this day and age where energy efficiency is something which many gravitate toward, anything with such a large number when it comes to power is instantly an attention grabber, in both positive and negative ways.
It's been quite a while since the first enthusiast targeted 1000 watt power supplies hit the market. There were 1000 watt power supplies before, mainly targeted at multi-processor servers and "heavy-iron", but never before had such a high-wattage power supply been targeted at the end user. The first units were from PC Power and Cooling, which were launched at around the same time as Nvidia's GeForce 7950 GX2 graphics cards, the first card capable of running in a Quad SLI configuration for four graphics cores. While these graphics cards certainly didn't require the massive power loads which a 1000W power supply could deliver, the coincidental timing of these two product releases was done in such a way that many buyers actually believed that they needed this kind of power supply. In reality, even power supplies as low as 500W could power a fairly powerful Quad SLI system configuration without issue.
In any case, while the first 1000W power supplies were criticized for being extremely expensive ($500-$700), loud, and largely unnecessary, they did help push the power supply industry forward. As nearly every power supply manufacturer rushed to bring similar 1000W units to market, prices have come down and features have improved. Nowadays, 1000W power supplies are frequently used in high-end enthusiast systems, as their price-tags aren't that much more in comparison to 750 and 800W units, and many users like the flexibility (and bragging rights) of having a 1000W unit under their hood.
From what we've seen, there are two types of people who are interested in 1000W power supplies. One being the person with a completely tricked out overclocked, multi-core, multi-GPU, multi-drive configuration who wants the most expansion capabilities possible. The other being the guy who wants to have a high-wattage PSU but not make full use out of it, hoping that the more efficient power supply will run cleaner and quieter in comparison to a lower-wattage unit working harder.
OCZ has a new power supply of which they're hoping will please both of types of user. Their latest flagship power supply is the ProXStream 1000W. The ProXStream is entering a burgeoning market of 1000W power supplies, although OCZ's unit appears to stand out in several ways, which we'll get to in the following pages. Here's how it looks on store shelves.
Features and Specifications
The Multi-GPU Ready ProXStream 1000 Watt power supply is designed specifically for the most demanding computing environments of PC enthusiasts, high-end system builders, and die-hard gamers. With today's top-of-the-line graphics cards consuming large amounts of energy, the ProXStream supplies stable and reliable power to quad-GPU platforms, as well as all your systems vital components.
On paper, the ProXStream shows both positives and negatives upon first glance. First off, the unit has the expected connector set for such a high-wattage power supply, with full support for both single and dual CPU motherboards (24-pin ATX + 4/8-pin secondary ATX), along with four PCI Express 6-pin power connectors, which are needed for the most high-end graphics configurations currently on the market today. OCZ uses four independent +12V rails, each capable of pushing 20A, plenty for any modern configuration.
Not necessarily a negative, but it's interesting to see the unit cooled by a single 80mm cooling fan, whereas other 1000W units typically have opted for 120mm fans (or larger), or dual cooling fans. Seeing a 1000W power supply cooled by a single 80mm fan would typically mean that the power supply is extremely efficient, or that the 80mm fan has to run at high speeds in order to keep the unit cool.
Therein lays one of the negatives of the unit, as OCZ does not list efficiency ratings for their power supplies. Most high-end power supplies will state if they meet 80% efficiency ratings or more, so with OCZ not listing their efficiency ratings, we would immediately think that their rating is lower than this level. In addition, one other negative which should be noted is that this power supply does not support 8-pin PCI Express 2.0 connectors. While there are only a scant few power supplies on the market which support this new connector, for such a high-end power supply which is brand new to market, we would have hoped to see this new connector in order to make the unit somewhat more future proof.
As for amperage ratings on the particular lines, let's compare the ProXStream to other 1000W units available on the market today.
|Design and Features|
Design and Features
The OCZ ProXStream 1000W unit has a flashy retail box, which includes the power supply itself, a US power cable, a small manual, and mounting screws. Here's the unit itself, in the flesh.
The unit is amazingly small for a 1000W power supply, as similar units form other companies typically require extended depth designs, which can require larger cases in order to be mounted properly. The OCZ unit, on the other hand, has the depth of a standard ATX power supply, meaning it can be mounted in nearly every standard ATX chassis on the market today. The entire design is fairly standard - no bottom mounted cooling fan, no honeycomb exhaust airflow access, we only see a few airflow slits on the sides of the unit.
Surprisingly short depth for a 1000W PSU
While our images make the unit look silver, or perhaps a gunmetal grey of some sort, in reality the unit has a highly reflective finish. While the unit is amazingly lacking in the "bling" department compared to other OCZ power supplies, the reflectivity does provide a nice visual flare. So, just how reflective is the finish?
Looking at the unit front to back, we can see the single 80mm fan exhaust output. If you look closely, right beneath the OCZ logo, there is a small PCB which is likely responsible for thermal monitoring. During our testing, we noticed that the power supply fan did not spin up or spin down based on thermal or power load, the fan spun at the same speeds at any given time. While OCZ claims the fan is low-noise, using "PowerWhisper" technology, our tests found that the OCZ cooling fan was noticeably louder than competing 1000W solutions. The fan was not loud enough to be a nuisance, but it does have to move a lot of air, and does produces an above average "wooshing" sound. Similarly rated units which use 120mm fans had lower noise levels, however, these units do require larger cases in order to handle their extended depth. Thus, if you want a 1000W power supply in a small depth form factor, be prepared for slightly louder noise levels. For such high wattage, the noise level is quite tolerable, but whisper silent this unit is not.
The rear of the PSU is somewhat busy. This 1000W unit comes with a heap of power connectors (which we'll detail on the following page), which are bundled in a rubber band by default. Looking at the rear of the PSU, we can see a fairly open design, which allows us to look at the PCB inside. Not only is there one PCB holding power components, but there are actually two individual PCB's in this power supply. This "double-decker" PCB design is likely how OCZ is able to get away with such a small form factor and cooling via a single 80mm fan.
Also worth noting, the OCZ unit does not have a hard power on/off switch, like most modern power supplies have. It's nice to have this extra level of control when setting up a system, allowing you to flip a switch instead of pulling the cord when you want to cut power.
After un-wrapping the rubber band which holds the connectors for shipping, we can see how many cables this power supply really has. Make sure your cable routing skills are up-to-par before trying to install this bad boy. The unit includes eleven total power cables, each with one to four connectors attached.
Cable bunch, unwrapped
We wish OCZ would have opted for a modular cable design for this unit, as most system configurations using this power supply will be left with several cables which will not be utilized, which means they must be routed elsewhere out of the way out of other components. With modular designs, you simply wouldn't attach these un-necessary cables. Adding modular connectivity would have likely added additional cost to the (already expensive) unit, and would have required a longer design in order to accommodate the modular PCB. This is a personal preference though, as I route my cables meticulously for optimal internal airflow. A good majority of users out there simply don't care though, and won't miss modular connectivity for their new high-end power supply.
On the plus side, OCZ has done a great job with the cable sleeving on this unit, which makes routing and bundling the cables easy. Each cable is covered with either red or black sleeving, the red sleeving specifically designated for PCI Express power connectors. This is a particularly nice touch, as it can be difficult to tell the differences between PCI Express and secondary ATX power connectors at time when working in the system.
OCZ also utilizes 4-pin Molex power connectors with easy-removal tabs, a definite plus. Instead of shaking an entrenched power connector out of place, you can simply apply pressure to the top and bottom tabs, and the connector will pop loose from the drive. It's the little things which count.
What about total connectors? Let's tally them up.
|Workstation Load Tests|
Our first set of power supply tests use a high-end workstation configuration, equipped with eight processor cores, 4 GB of memory, a high-end graphics card, and three high-speed hard disks. Our goal was to test the efficiency of these power supplies under different load levels, ranging from sitting idle, maximizing the processors, maximizing the graphics, and the most intensive test, maximizing both processors and graphics at the same time. Wattage/amperage numbers were watched with a hardware power line meter which updates every second. Numbers were taken at the stabilized power level for that specific task.
All of our power supplies had the necessary connectors to handle this configuration, and all handled this high-end configuration without a sweat. Let's see which power supplies handled the load better though.
Despite not listing efficiency numbers on their box, the OCZ ProXStream 1000W unit, is indeed, highly efficient. Our high-end workstation configuration ate up about 450W of actual power load throughout our heaviest benchmarks, but throughout each test, the ProXStream shows the lowest actual wattage levels pulled, which is a very positive attribute for OCZ to have. Our tests show the OCZ ProXStream providing similar efficiency levels to that of Corsair's HX620 PSU, which is rated at 80% efficiency. Even an eight-core system with a top of the line graphics card doesn't pull anywhere close to 1000W.
|Gaming Load Tests|
Our second set of tests maximizes GPU load by throwing dual GeForce 8800 GTX cards in an SLI configuration into the mix. Only three of our five power supplies could compete here, as they have the necessary 4 x PCI Express power connectors in order to power this configuration (each GeForce 8800 GTX card requires dual 6-pin PCI Express power connectors).
Our 8800 GTX SLI configuration shows similar results as our workstation tests. This high-end gaming configuration utilizes the least amount of actual power from the line socket when the OCZ ProXStream 1000W power supply is used. There isn't a major difference between the OCZ unit and our Enermax/Silverstone high-wattage units, as all three units were able to handle this configuration without breaking a sweat. However, the OCZ unit puts up the best numbers across the board here as well.
As OCZ's first 1000W power supply, we will certainly say that the ProXStream 1000W unit is a successful product, as it's able to handle the fastest configurations we could throw at it without a hitch, and it has enough connectors for just about every possible system on the market. The unit currently has a price tag of about $350, right on par with other 1000W units on the market today.
While we do like this power supply, as it does exactly what it states without any issues, there are some aspects we like and dislike at this time. As for the good aspects, we like the unit's short depth, as it means the unit will fit in the vast majority of cases on the market without hassle. We also like OCZ's excellent cable sleeving, especially in regards to the red sleeved PCI Express power lines - a very nice touch.
For possible future revisions, we would urge OCZ to move to a single 120mm cooling fan instead of a single 80mm fan, since the single 80mm fan is significantly louder compared to similar wattage units using 120mm fans. We would also like to see modular cabling, and prefer a dedicated on/off switch. None of these items detract from the unit's functionality, but the unit lacks some of the nice touches which some other high-end 1000W power supplies have.
We have to give credit to OCZ for shipping an extremely efficient power supply. Both our workstation and game rig tests showed the ProXStream being the most efficiency high-end PSU in our tests, beating out established competitors across the board. Considering how efficient the unit is, we would recommend OCZ to advertise this feature, as it's one which technical users will indeed care about. All in all, the OCZ ProXStream 1000W is a high-quality power supply which demands top dollar, but delivers lots of clean power in a surprisingly small form factor. Well done OCZ.