Corsair HX750W Professional Series ATX Power Supply Review

Eric Garay

15 years ago

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Hyperthreads, multi-core, full load, and stability are just a few of the words and phrases that accompany today’s most powerful Intel Core i7 and AMD Phenom II Processors. These chips are calculating and execution monsters that are capable of crashing through every performance record. However, you’re not going to smash through any records if you connect some sheepish power supply to your new state of the art ninja killing system. That’s why you’ll need a very formidable PSU like the Corsair HX750W Professional Series ATX Power Supply. Let’s check this beast out!

Features and Specifications

I’ve heard from different technicians throughout the industry that have repeatedly recommended the HX Series for one main reason: Reliability.

Corsair states that the HX Series is designed and engineered to ensure stable, clean, and reliable voltages essential to high-end gaming PCs and workstations. With an 80 Plus Silver certification standard reaching upwards of 90% energy efficient, it’s no wonder it comes so recommended.

It also offers a massive 62A single +12V rail as opposed to multiple. That’s because multiple +12V rails don’t always equate to the best power available. Rather than lay six paragraphs of technical misery, let’s just say there is nothing wrong with a massive, beefy single +12V rail.

To sum up the power supply’s best features, it supports ATX 12V 2.3, EPS12V 2.91, and older ATX12V 2.01 systems. The PSU provides 25 Amps to both the +3.3V and +5V rails. That’s a perfect amount of power since the bulk of it goes to the +12V, as it should.

What’s In The Box?

Pulling the HX750W out of the box reveals that the PSU itself comes wrapped in a black velvet bag. Though not really that useful after you install it, I found it to be more useful for holding all the extras that are left over.

Another black pouch holds all of the important modular wiring including the power cable. Everything is nicely wrapped and organized. There are 2 x Floppy wires, 2 x 4-pin standard wires, 2 x 6-pin PCIE, 2 x 8-pin PCIE, and 3 x 3-lead SATA cables. You’ll also find a little bag with zip ties and other items to help tidy up the wiring.

Rounding this off is a very simple manual made specifically for novice users and will make finding what you need to install the HX750W power supply very easy.

The Massive Beast Up Close

Overall, the HX750W isn’t all that flashy. It’s not an ugly beast mind you. Just an all around jet black, solid power supply with a Corsair badge on the 120mm cooling fan. The PSU’s finish exudes an “industrial” feel and exhibits a very healthy weight. Extra weight typically means that more was spent on internal components that improve performance. “Bling” doesn’t always equate in to quality. We can think of several power supplies over the years that looked good but didn’t perform.

Taking a look at the wiring and modular sockets, you can see the main 24-pin power and 8-pin 12V Auxiliary leads are permanent. These provide the bulk of the computer’s power which ensures optimal connection. Since these have to be connected at all times, it also saves you money not making it modular.

Checking Out the Circuits

You can see that there isn’t a fancy spread of heat sinks. Instead, there are three very thick, black aluminum heat sinks standing straight up. That’s not a big deal especially when the transistors are of rather good quality. Again, function is more important than fashion. Having a less cluttered heatsink layout can also make things cooler due to uninterrupted air flow.

The same can be said for the two maroon capacitors in the corner. These are two 420V capacitors that keep all of the rails powered at all times. This will also account for how clean and reliable the PSU’s amperage is during half and full load operations.

Test System

Normally, I test my systems at full load by installing two Zotac NVidia GTX295 video cards along with my Intel Core i7 975 based system. While the system would undoubtedly not require more than 750 Watts during regular use, it would peak beyond that during initial boot and at maximum load. So instead, we’ll use something more modest, but just as demanding.

Our test system as configured includes:

Intel Core i7 975 “Bloomfield” Processor
GIGABYTE GA-X58 Extreme LGA1366 Motherboard
Kingston HyperX 6GB 2000MHz DDR3 Triple Channel Memory
Zotac Geforce GTX295 Video Card
Western Digital 2x500GB Striped
Windows 7 64-bit Professional
GTX260 (for Physics and Power Consumption)

As with all test builds, the latest BIOS, firmware, and/or drivers were installed. The Zalman ZM-MFC2 was used to track the PSU’s power consumption. And, a trusty industrial Volt Meter was used to measure the power rails and watch for voltage fluctuations during testing.

The HX750W Test Results

The most important test is the Load test. This is where we find out if the PSU can maintain its rated maximum wattage and efficiency. Then, for extra credit purposes, the PSU is pushed past its specs to see how far it’ll go before protective circuits do their job.

As you can see, the HX750W more than sufficiently maintained its 750 Watt output with flying colors. It was even 90% efficient which was not expected. Voltage fluctuations recorded during Load were extra minimal. The 3.3 and 5V rails were pretty much solid across testing. As with any PSU, the 12V rail showed a maximum .03 fluctuation during operations.

The design of the HX750W (two big boy capacitors) suggest there’s more underneath the hood. With that in mind and the PSU connected to a capable tester, the PSU eventually maxed out at a whopping 895 Watts. The protection circuits did a fine job.

What was really nice to see is that the PSU maintained an 88% efficiency. And, equally impressive was that the +12V massive rail didn’t go below +12.03V. In terms of performance, this is excellent. Going for the hat trick, the HX750W did in fact power the system with the two GTX295 video cards installed. The system never became unstable or failed to run 3DMark Vantage.

Final Thoughts

As far as I’m concerned, the PSU’s most impressive feature is its ability to maintain the amperage on each power rail, especially the 12V, at 100% load and beyond. In fact, it seems like the PSU is built with quality of output over quantity achieving a 90% efficiency. Could it be its built for more power, yet rated lower? Probably, but who’s complaining?

The Corsair HX75W Professional Series Power Supply earns itself extra credit as it continues to provide power well beyond specs. The extra performance is equivalent to getting some ice cream with your cake. You not only get what you paid for, but you also get a great deal more power output as insurance.

At a current price tag of $139.99 with a nice rebate at Newegg, it’s still cheaper than the bulk of the 80Plus Gold PSUs available. Plus, it’s much, much cheaper than the 850W Gold Plus PSUs as well. Base on value, performance, recommendations, and a 7 year warranty, it deserves nothing less than Editor’s Choice.

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