We were impressed to see that Corsair HX1000W is internally practically identical to Thermaltake Toughpower 1,500 W, a unit labeled with a maximum power capacity 50% above Corsair’s model!

There are three major differences between Corsair HX1000W and Thermaltake Toughpower 1,500 W, though. First, the modular cabling system has a different configuration. On Corsair HX1000W there are six connectors for peripheral and SATA cables, while on Toughpower 1,500 W there are only four. On the other hand, on HX1000W there are four connectors for auxiliary video card power cables, while on Toughpower 1,500 W there are six.

The second major difference is on the use of two virtual rails on each +12 V rail on Toughpower 1,500 W, feature not present on HX1000W. This means that each power supply inside HX1000W uses a single-rail design, while each power supply inside Toughpower 1,500 W uses two virtual rails, for a total of four +12 V rails. The difference between a single rail design and a multiple rail one is how the over current protection (OCP) is connected. On single rail design there is only one OCP circuit that monitors all the +12 V outputs at the same time, while on multiple rail design the power supply has several OCP circuits, each one monitoring a group of +12 V wires (the virtual rails).

And the third difference, and here Corsair HX1000W has an advantage, is that all capacitors on the secondary are solid. On Toughpower 1,500 W only the capacitors used on the +5 V and +3.3 V rails are solid.

We are pretty confident that Corsair HX1000W is in fact a 1,500 W power supply that Corsair decided to label as a 1,000 W model because of efficiency. If Corsair had labeled this unit as a 1,100 W or greater unit it wouldn’t achieve the minimum 80% efficiency at full load that is considered by today’s standards the minimum a power supply should perform.

The efficiency from this power supply is decent (between 80.0% and 83.1% depending on the load), put there are 1,000 W units around that present higher efficiency, like OCZ EliteXStream 1000 W.

The number of cables available on this unit is outstanding and will allow you to build a three-way SLI using three GeForce GTX 260 or GTX 280 directly without the need of using any kind of adapter on the power supply, as it has six video card power cables (each GTX 260 or 280 will take two cables). However if you want to install four very high-end video cards from ATI you will need to use adapters to convert peripheral power plugs into video card auxiliary power plugs for the fourth card.

The overall internal quality of this power supply is outstanding. Besides the solid aluminum caps on the secondary, it uses a Japanese cap on the active PFC circuit labeled at 105º C. Remembering that this power supply uses a dual-transformer design with independent circuits, making this power supply to have two separated power supplies inside. The only circuit that is shared among the two internal power supplies is the rectifying bridge. Usually power supplies with two-transformer design shares the active PFC and switching sections, which isn’t the case with HX1000W.

And the price of this baby is not even close to its main competitor, Thermaltake Toughpower 1,000 W – which curiously uses the exact same design of this power supply. Corsair HX1000W can be found, on average, by USD 235, while Toughpower 1,000 W costs, on average, USD 290 (prices for the US market).

In summary Corsair HX1000W is a practically flawless 1,000 W power supply clearly targeted to users with three or four very high-end video cards and several hard disk drives. Of course if you are building a more modest system with only one or two video cards, you should buy a more inexpensive product, which will give you a better cost/benefit ratio.