We were really impressed by OCZ EliteXStream 1000 W. It can really deliver 1,000 W at 50º C with one of the lowest ripple and electrical noise levels we’ve ever seen. You will get a high efficiency with this power supply if you pull up to 60% of its labeled capacity (600 W): between 83.5% and 85%. With 80% load (800 W) efficiency dropped to 81.5%, still above 80%. But when we pulled around 1,000 W efficiency dropped below the 80% mark: 78.2%. This is not really a problem, as high-wattage power supplies are targeted to users that what to run them at half of their labeled capacity in order to achieve the best efficiency possible (click here to learn more about this question). You will never be able to pull anywhere close to 1,000 W with a personal computer.

This is a good product, especially when you compare it to the previous 1,000 W unit from OCZ, the ProXStream, which has a lousy efficiency (79% when you pull 800 W, only 74.5% when delivering 1,000 W), a small and noisy fan and a very serious heating problem due to its excess of components squeezed into a very small form factor combined with an inefficient fan.

ProXStream costs less, but please stay away from it. EliteXStream is a little bit more expensive but is worth every extra penny. In fact, it is cheaper than other 1,000 W models like Corsair HX1000W and Thermaltake Toughpower 1000 W.

Of course there must be a trade-off for its lower price and this can be found on the lack of a modular cabling system and a reduced number of power cables for video cards.

The presence of only four video card cables is the main drawback from this product (even though all of them use 6/8-pin connectors, which is an advantage), because it limits you from installing more than two very high-end video cards with two auxiliary connectors each without the use of adapters, and we believe that most people looking for a 1,000 W product will have more than two video cards. Of course you can use adapters on the peripheral power plugs to get the extra connectors you will need.

If this limitation doesn’t bother you, go ahead and buy OCZ EliteXStream 1000 W: it is one of the 1,000 W power supplies with the best cost/benefit on the market today.