OCZ ProXStream 1kw OCZ1000PXS ATX PSU Page: 1

Up until recently 1000w of power was only available to those of us with plenty of space inside our PC cases. This was a problem for a lot of people as they wanted to be able to run the latest and greatest Quad/SLI and Crossfire set-ups but just simply didn't have the space for the over-sized (and highly expensive) units that were available at the time.

In the past few months several manufacturers have made it their mission to fill this gap in the market by attempting to cram the full 1000w into units suitable for fitting into standard sized ATX cases. In all honesty most attempts have been pretty poor, with most models not being able to hold up the full 1000w for any sustained period, being extremely noisy and/or ending up so hot that you could fry an egg on top of them.

Will the recently released ProXStream 1000w PSU from the enthusiast orientated manufacturer OCZ be the answer to our prayers? Read on to find out.


The following information has been shamelessly copied directly from OCZ's website:

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.

The new OCZ ProXStream 1000W PSU utilizes a powerful, server-class core and merges it with an unparalleled compact form factor to accommodate virtually all computer cases, a requisite for today's enthusiasts and system-builders.

The most powerful and compact PSU comes backed with an industry-leading warranty, and OCZ offers an exclusive 3 year PowerSwap warranty program for unsurpassed peace of mind.

• 1000W Configuration
3 year warranty backed by OCZ’s exclusive PowerSwap™ replacement program. No more endless return-for-repair loops!
Internal 80mm fan
4 Channel 12V Output provides stable electric power to computer components
4 Channel PCI-E connectors
Dual CPU support: provides 8-pin 12V dual CPU support with stable voltage
20+4 pin: compatible with all motherboards available on the market
4pin & 8pin: accords with the requirements of CPU in ATX or EPS 12V V2.91 systems
Active PFC: enhances utilization of energy
Over Voltage and current protection: A complete protection circuit is implemented, protecting every component in your system.
Environmental protection specifications: accords with WEEE & RoHS by Europe 115Vac 60Hz / 230Vac 50Hz
• Rail Layout: +3.3V(28A), +5V(30A), +12V1(20A), +12V2(20A), +12V3(20A), +12V4(20A)

In terms of specification the ProXStream looks like a very capable unit. With a total of four +12v rails rated at 20a each and a combined +12v output of 70a the PSU certainly can't be accused of being underpowered. The same goes for the +3.3v and 5v rails rated at 28a and 30a respectively.

Anyway, enough of the boring stuff, let's get down to the nitty gritty...

OCZ ProXStream 1kw OCZ1000PXS ATX PSU Page: 2

The first thing that struck me about the ProXStream when unwrapping it from it's delivery box was the disproportion in its size compared to its weight. We already know that the ProXStream has been designed to fit inside any standard ATX case and thus the size of the packaging is fairly modest, but in terms of weight the unit was a fair bit heavier than I was expecting.

OCZ ProXStream 1kw Box OCZ ProXStream 1kw Box

OCZ ProXStream 1kw Box OCZ ProXStream 1kw Box

The ProXStream is presented in a very visually attractive cardboard box printed with a brushed aluminium and blue 'techno' style background. The front and back of the box include basic deatails on some of the units most prominent features which include: Quiet Operation, Multi-GPU Ready, 3yr Warranty and a Compact casing. Turn the box around to the side, and we can see that OCZ have included a table showing the output of each rail on the unit.

OCZ ProXStream 1kw Package OCZ ProXStream 1kw Package

Open the box and we can see that OCZ have chosen to package the ProXStream inside a bubblewrap bag and pad the remaining area of the box out with two styrofoam layers. This should be enough to protect the unit from modest knocks and bumps, but is lacking slightly when compared with OCZ's lower spec'd EvoStream 600w unit.


Just about every PSU to come out of OCZ has had one thing in common with it's predecessors - and Electroplated gunmetal finish. The PowerStream had it, as did the ModStream, then the EvoStream and I'm happy to see that the ProXStream is no different.

OCZ ProXStream 1kw Top OCZ ProXStream 1kw Label

OCZ ProXStream 1kw Back OCZ ProXStream 1kw Surface

I've always been a big fan of Electroplating as in my opinion it looks classy, produces a high quality mirror finish and can only really be beaten by an expensive paint job. This highly reflective surface does however have a tendancy to pick up lots of fingerprints, and unless you are planning on wearing mittens while installing the ProXStream, you will make a mess of it.

I'm extremely happy to see that OCZ have placed the specification sticker on the top of the unit, rather than at the side like most manufacturers. This means the ProXStream's sexy finish can be seen once the unit has been installed in your case, without a large sticker getting in the way.

At the back of the unit we can see that OCZ have opted for an 80mm fan to keep things cool. What I found immensely strange was the lack of a power switch. Although this is technically not required (as it's almost just as easy to pull the plug out), I felt quite cheated and couldn't help but stare at the void where the switch should have been.

OCZ ProXStream 1kw Side OCZ ProXStream 1kw Side

Both sides of the ProXStream feature ventilation grills which are actually quite pointless as they appear to be covered by plastic sheets from the inside of the unit. Whether or not this will have any effect on the cooling efficiency of the unit is yet to be seen.

OCZ ProXStream 1kw Front OCZ ProXStream 1kw Sleeving Problem

The front of the PSU is comprised entirely of a very generously sized grill, which should provide the unit with ample breathing space for the 80mm fan to do its job.

Unfortunately as you can see from above, the sleeving on the sample we received did not go far enough inside the unit, leaving us with some frayed braiding around the edges.

OCZ ProXStream 1kw OCZ1000PXS ATX PSU Page: 3

Having been extremely impressed with OCZ's GameXStream units in the past I was willing to bet money on the ProXStream being a slightly upgraded version of their 850w model. To me this would have made perfect sense as the GameXStream was a very stable, quiet and efficient PSU. However, let's take a look inside the ProXStream to find out exactly what is behind its 1000w of power.

OCZ ProXStream 1kw Internals OCZ ProXStream 1kw Internals

OCZ ProXStream 1kw Internals OCZ ProXStream 1kw Internals

Much to my surprise the ProXStream couldn't have been more different internally to their highly awarded GameXStream series. As you can see from the images above, the ProXStream makes use of a two level PCB and is actually manufacturered by the same company that produced the EvoStream 600w.

Without a doubt the ProXStream is one fully packed PSU. So much so that I found it near impossible to remove the upper PCB to get some good pictures of what was contained underneath. More to the point, OCZ's choice of a single 80mm fan is slightly worrying as the fan is positioned on the left-hand side, meaning components on the other side of the unit will see very little airflow.

OCZ ProXStream 1kw Pots OCZ ProXStream 1kw Plotech

The ProXStream has several adjustable potentiometers (pots) on the upper PCB that are often responsible for fine-tuning the output voltages of the unit. However, a layer of glue as been applied to the pots to prevent them from being tampered with.

OCZ ProXStream 1kw Fan

As previously mentioned, the unit is cooled by a single 80mm fan manufactured by Protechnic Electric. Unfortunately I was unable to find any definite specifications for this fan and can only assume that it is similar in performance to the MGT8012YB model used in the EvoStream (31.9dbA @ 2400rpm).

Cables & Connectors

All cables on the ProXStream are finished in black sleeving with the excepton of the PCI-E connectors which are easily identifiable in red. All molex connectors feature the 'easy grip' design that makes removal of the connectors from devices easier.

OCZ ProXStream 1kw Cables OCZ ProXStream 1kw Cables

It's good to see that OCZ have decided to sleeve all cables right to the tip just like on their GameXStream series. Many manufacturers only sleeve some of the cables, or sleeve up to the first connector on every cable. The sleeving job is professional with cable ties holding the sleeving in place, and heat shrink keeping everything neat and tidy.

OCZ ProXStream 1kw PCI-E OCZ ProXStream 1kw ATX

The ATX connector on the ProXStream is native 24-pin. However, as you can see above, a small block of 4 connectors can be broken off to switch the connector to 20-pin, and thus make it compatible with older motherboards. As many motherboards still make use of the P4-12v 4-Pin connector, OCZ have chosen to include two separate cables for P4-12v (4-pin) and EPS12v (8-pin) standards.

Unlike the recently reviewed 1kw Giant Reactor from NorthQ, OCZ have decided to use 4 seperate cables for the PCI-E connectors (rather than 2 cables with 2 connectors). This should provide slightly better voltage ouput to the cards when used in Quad-SLI mode.

OCZ ProXStream 1kw OCZ1000PXS ATX PSU Page: 4
Load & Efficiency Testing

To provide our readers with the most accurate results, Overclock3D uses a custom built PSU load tester on all reviews. This not only gives much more reliable results than the testing methods employed by other sites, but also allows for all current and future review results to be compared side-by-side.

Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains (Mains Draw) against the power consumed by the OC3D power supply stress tester (PSU Load). These results may not be 100% accurate, but have proven to be extremely close to results obtained from professional equipment.

  0% 50%100%
+3.3v Rail
0w33w 66w
+5.0v Rail
0w50w 100w
+12v Rails

OCZ ProXStream 1kw Load Tests OCZ ProXStream 1kw Efficiency Tests

It has to be said that the ProXStream performed surprisingly well in our tests when placed under a full load of 886w. Unfortunately we couldn't stress the unit up to the full manufacturers rating of 1000w, but even at 886w it was clear to see that the unit wasn't breaking into a sweat. The +5v rails suffered the most during the tests - dropping from 5.03v to 4.83v, but still remained within ATX specifications.

Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester. These results may not be 100% accurate, but have proven to be extremely close to results obtained from professional equipment. With this in mind, our testing equipment indicated that the ProXStream was able to manage a fairly average 81.26% rating when placed under 443w load, and a more respectable 82.19% when under 886w load.

Heat Output Testing

In our continuing efforts to make power supply reviews more thorough, rather than simply checking voltage stability, Overclock3D will now be recording the temerature of each PSU as it undergoes testing. Temperature recordings will be taken from the underside of the PSU's outer casing at 0%, 50% and 100% load levels in an attempt to gauge how much heat is likely to radiate into the end-users case.

OCZ ProXStream 1kw Temperature Tests

It's hard to deny that heat is a big problem on the ProXStream 1kw unit. With only a single 80mm fan trying to keep 2 layers of components cool it's no surprise that the ProXStream is one of the hottest PSU's under load that we've tested to date. Installing an additional 80mm fan on the other side of the unit may have alieveated this, but unfortunately due to the extremely cramped interior, I very much doubt this could have been possible. If you don't have sufficient cooling inside your PC case, the additional heat dump from the ProXStream could prove to be a slight problem.

Noise Level Recordings

Possibly the hardest part of any PSU review is summarising the level of noise given out by the unit. The threshold for what is considered 'noisy' varies from person to person and therefore what I may consider a quiet unit, another person may consider extremely loud. A common way to resolve this issue is to use a dBA meter to measure the units noise level, however this doesn't take into account the pitch (type) of noise emitted and whether it is likely to irritate end users.

For this reason OC3D records all power supplies at idle and load in wav format for you to make your own informed decisions. All recordings are taken at 30cm away from the PSU and outside of a PC case. You will need to remember that noise levels will be reduced by varying amounts once the PSU has been installed inside your PC enclosure.

0% Load Recording - Download
50% Load Recording - Download
100% Load Recording - Download

As you can hear from the recordings above, the ProXStreme is not a quiet unit. Even under 0% load it seems like the 80mm fan is running at near full speed. Why this amount of airflow is required when there is no stress on the unit I'm not sure, but this issue certainly rules out the ProXStreme as a viable option for the silent PC enthusiast.

OCZ ProXStream 1kw OCZ1000PXS ATX PSU Page: 5

The OCZ ProXStream 1000w is a great looking unit with stable voltages all the way up to 886w and quite possibly beyond. The tweakers among us will be delighted to see that the ProXStream has internal pots that can be used for fine tuning the output voltages (providing you can remove the anti-tamper glue), and with an efficiency of over 81% the unit should also appeal to those who are looking to save valuable pennies on their energy bills.

Unfortunately due to the way that the ProXStream is crammed with two levels of circuits, the unit gets very hot. To counteract this OCZ have installed a high-cfm 80mm fan that unfortunately can only be described as a leaf blower when running at full speed.

If noise isn't a factor in your next PSU purchase, then the OCZ ProXStream can be found over at SpecialTech or Tekheads retailing for around £195. This is rather expensive considering the minimalistic package you get when compared with other 1kw power supplies on the market, and personally I was expecting it to be at least £20-30 cheaper.

Update 04/03/07
We have been informed that the OCZ ProXStream 1kw has been reduced in price by £20 over at SpecialTech. This brings the retail price down to £175 making the ProXStream far more competitive in the 1kw market. For this reason, the price sub-score has been increased from 7 to 8.


• Great looking electroplated finish.
• Sleeved cables and easy grip molex connectors.
• Good efficiency at medium and high load levels.
• Fairly stable voltages when tested up to 886w.
• Standard sized ATX casing. Suitable for all PC's.
• Adjustable pots for tweaking voltage output.

• Very noisy even with 0% load.
• Unit gets hot under heavy load.
• +5v rail results could have been better.

Recommended Award

I'd like to extend our thanks to OCZ for providing the ProXStreme 1kw for review.

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