The HX line-up includes four models with capacities ranging from 750W to 1200W. The biggest difference between Corsair's HXi and HX models, besides the latter's lower price, is the lack of software control/monitoring, since a digital interface circuit is missing from the HX family. Both the HXi and HX PSUs use the same 135mm FDB fan. It's incredibly quiet, even at high speeds, so we expect these lower-cost models to still feature great acoustic profiles under any circumstance.
Apparently not every enthusiast wants a power supply with digital circuits. Some have no intention of connecting their PSU and motherboard, believing that simpler is often better. This also gets around an extra installation step, even if it's just one cable and some extra software.
According to Corsair, the HX1200i and HX1200 we're reviewing today are separated by only $10. We figured the HX1200 would be significantly less expensive, making it more attractive. But that tiny delta compels us to lean towards the HX1200i, frankly. The only HX model with a notably lower price tag than its HXi equivalent is the HX750, which costs $30 less.
At least all of the HX units are similarly modular, with the ability to toggle between one and multiple +12V rails through a switch on the PSU's rear panel (where the modular cables plug in).
The same warranty that covers Corsair's highest-end PSUs also applies to the HXes, giving you 10 years of protection. With the cryptocurrency craziness in full swing, we expect a lot of HX units to power mining rigs operating at nearly full load continuously. Under such harsh conditions, a 10-year warranty could prove catastrophic if RMAs start rolling in at an accelerated rate. We don't think any power supply will last for prolonged periods of time under the kind of duress that mining imposes. We've even heard that some companies are thinking about cutting their coverage if a PSU is used for mining, though we're not sure how they plan to prove this.
Corsair's HX1200 achieves a Cybenetics ETA-B rating and an 80 PLUS Gold certification. When it comes to noise, it is LAMBDA-A+-rated, indicating very quiet operation. The list of protection features is thorough; Corsair even offers OCP at +12V through a switch, located on the back of the PSU.
The 135mm cooling fan uses a fluid dynamic bearing, so it should last quite a while. In a PSU backed by a hefty 10-year warranty, the fan has to be super reliable.
A 20cm depth makes this a long PSU, indeed.
The minor rails boast an impressive 150W of maximum combined power, while the +12V rail can deliver up to 100A if needed, handling the PSU's full power on its own. Lastly, the 5VSB rail is also quite strong with 17.5W capacity. We like to see 1kW+ PSUs with beefy 5VSB circuits.
In the multi-+12V rail mode, there are eight +12V rails with 40A maximum current output each. All of the rails combined can deliver the same wattage (1200W) in single-rail mode, of course.
Cables & Connectors
There are two EPS connectors along with eight PCIe ones, all available at the same time. The number of SATA connectors is huge, while the eight four-pin Molex connectors should cover every need. Some miners would probably ask for 10 or 12 PCIe connectors, but Corsair obviously didn't have a cryptocurrency boom in mind when the HX1200 was being designed.
As mentioned, there is a switch that lets you choose between one +12V rail or multiple ones. In the HXi models, this is achieved using the Corsair Link software. However, since the HX models don't have a digital interface, a different approach had to be used.
The +12V rails can deliver up to 40A each if the multi-rail mode is selected. According to Corsair, each individual connector in this PSU has over-current protection, so no more than 40A goes through any given cable.