It is very important to notice that Corsair HX750W, HX850W and HX1000W have nothing to do with other models from this same series. They use a complete different (and better, by the way) design using a DC-DC converter to generate their +5 V and +3.3 V outputs, like several other high-efficiency power supplies (PC Power & Cooling Silencer 910, Antec Signature, Antec TruePower New, Seasonic M12D and Cooler Master UCP series). These HX models are manufactured by CWT, while other models from HX series are manufactured by Seasonic. Why Corsair kept the same name is a mystery. In our opinion they should have used a different name so consumers would know they are facing a different product class, targeted to users looking a power supply with high-end parts and very high efficiency.
Something interesting happened with this power supply 80 Plus certification. According to 80 Plus this unit, together with HX850W, is Gold certified – minimum efficiency of 90% at typical load (50% load, i.e., 375 W) and a minimum efficiency of 87% under light (20% load, i.e., 150 W) and full (750 W) loads –, however since the results achieved by 80 Plus were so close to these minimum requirements Corsair decided to downgrade these two units to Silver (88% under typical load and 85% under light and full loads) by themselves. On a market that usually manufacturers like to exaggerate about product characteristics it is really nice to see a manufacturer doing exactly the opposite: reducing the numbers to protect users. Kudos to Corsair.
Corsair HX1000W uses two transformers inside, while HX850W and HX750W use only one. Since we have already reviewed HX850W, on this review we will spot the internal differences between the 750 W and the 850 W models.
HX750W has the same size as HX850W – 7 3/32” (180 mm) deep –, being long units. Both have a 140 mm fan on its bottom, feature active PFC, have a single-rail design and a modular cabling system.
On Corsair HX750W the main motherboard cable (20/24-pin) and the ATX12V/EPS12V cable (two ATX12V connectors that together form an EPS12V one) are permanently attached to the unit. These cables are protected with nylon sleevings that come from inside the power supply housing. The 850 W model has two more cables coming directly from inside the power supply (two auxiliary power cables for video cards with one six/eight-pin connector each), feature not available on the 750W version.
Like HX850W, the modular cabling system from HX750W has ten connectors and the reviewed power supply comes with nine cables (one less than HX850W; the cable that is missing is one extra peripheral power cable) plus two adapters to convert standard peripheral power plugs into floppy disk drive power plugs. The cables included are:
- Four auxiliary power cables for video cards, with one six/eight-pin connector on each one of them.
- Three SATA power cables with four plugs each.
- Two peripheral power cables with four plugs each.
The number of cables and connectors available is perfect for a 750 W product, allowing you to have up to 12 SATA peripherals and up to two high-end video cards. Of course you can have more than two video cards, but in this case you will need to convert standard peripheral power connectors into video card power connectors.
The main motherboard cable, the ATX12V/EPS12V cable and the video card cables are long, measuring 23 5/8” (60 cm), so you probably won’t have any trouble using this power supply on a big full tower case. Peripheral and SATA power cables have a distance of 17 ½” (44 cm) between the end that goes on the power supply and the very first connector on the cable. The distance between each connector on these cables is of 4” (10 cm).
The main motherboard cable use 16 AWG wires, which are thicker, while all other wires are 18 AWG, which is the correct gauge to be used.
Now let’s take an in-depth look inside this power supply.
- 1. Introduction
- 2. A Look Inside The HX750W
- 3. Transient Filtering Stage
- 4. Primary Analysis
- 5. Secondary Analysis
- 6. Power Distribution
- 7. Load Tests
- 8. Overload Tests
- 9. Main Specifications
- 10. Conclusions