Antec HCP-850W Power Supply Review

Antec was kind enough to send Overclockers.com a shiny new HCP-850 W power supply to review, this is Antec’s second model in the High Current Pro (HCP) series. While it is related to the HCP-1200 W in name and efficiency the internals are almost certainly significantly different. We will, of course, check!

Features and Specifications

Following are the features and specifications of this HCP-850 W power supply, directly from Antec:

The input ratings:

The output ratings, which are arguably more important, are also more complicated.

But wait, that’s not all! There are a fair number of certifications as well, they include the following:

• EuP 2010 requirement (5vSB < 1w)
• RoHS
• Nvidia SLI
• AMD Crossfire-X
• 80+ Gold
• AQ5 Antec Quality
• A raft of safety certifications: cUL, TUV, CE, CB, FCC, C-TICK, CCC, BSMI, Gost-R

Whew, that was intense!

In short, this unit is certified for pretty much everything, can cough up over half of its output on a single 12 V rail and can produce all but ten watts of its total output on the combined 12 V rails, all while being quite efficient!

With all that out of the way, lets take a look at the box the HCP-850 comes in, as well as the PSU itself.

The Box, PSU, and Cables

As you can see the box is nicely laid out, the front is quite clean for a modern hardware box, I like it!

Let’s open the box and see if there is a power supply inside. I certainly hope so. Otherwise, this is going to be a very short review indeed.

That’s a well packed power supply, there’s a lot of cardboard between it and the outside world, and it is stuffed into a nicely fitting sack. Unlike many such sacks, this one is fitted specifically to the PSU and is closed with Velcro. Very nice!

This is a nice looking power supply! The dark blue color came out a bit lighter in the pictures than it really is, it took me a bit in person to notice that it wasn’t black. This thing is heavy, too! That’s a good sign.

There are three hardwired cables, the ATX12v, the EPS12v (cpu power) and a PCIe cable with two 6+2 connectors on the end of it. Odds are excellent that if you’re building a rig that needs this juicy of a power supply you’ll need that and more, so this seems like a reasonable choice by Antec. The cables themselves are quite long, which is a nice feature for those of us with full tower cases, but may make cable management difficult in a smaller case.

Now let’s look at the modular cables themselves.

Think there are enough of them?  It’s certainly a wide selection!

Across the top, we have the very beefy power cord and a second EPS12v cable in case you have a dual-CPU motherboard or a high end one like Asus’ Rampage 3 Extreme, and four black screws.

From left to right, across the bottom, are two more PCIe cables, each with two 6+2 connectors. Following them are three SATA cables, each with three connectors, the last of which is a straight connector rather than the standard right angle connector. Last are two Molex cables, one of them has a FDD connector and both have three Molex HDD power plugs. These cables aren’t short, either. It would take a spectacularly large case to run into length issues.

Now here’s a nice feature, you can plug the SATA/Molex cables into the red PCIe/EPS12v slots on the power supply!  Admittedly you would be hard pressed to plug all of them in if you couldn’t, but it’s still refreshing.

Methodology & Testing

First, a bit about testing power supplies. Unlike most computer parts, power supplies require rather specialized equipment to test correctly. Sure, you can plug it into a computer system and see if it can run a 980x and a couple GTX580s, but that doesn’t tell you how much power the PSU is putting out, nor what that voltage looks like. Worse, if the unit is defective or simply underbuilt/over rated the unit can fail catastrophically and take your computer along with it!
Hence, you really need a load that is strong enough to stand up to a PSU dying while attached to it!  Purpose built loads and the testing units to run them cost thousands of dollars. They’re easy to use and very accurate and definitely the ideal way to test power supplies, but also entirely too expensive for me to afford. Instead I have built my own! It’s entirely mechanical and not automated in the slightest, but it can put a serious load on a PSU and survive the PSU failing in the process.  The down side is that it doesn’t have the built-in current sensing that a professional grade unit does, so PSU efficiency is difficult to nail down.

The second part to a good PSU review is an oscilloscope to look at the outputs and check for ripple (I’ll talk about what ripple is in the ripple section), for this purpose I have a BK Precision model 1472B analog scope. It has its pluses and minuses compared to more modern USB scopes. On the minus side, taking pictures of it is a difficult operation at best as you’ll see. On the plus side, it has incredible sensitivity at high frequencies, something that many USB scopes lack.

Lastly, a voltage meter is required, I have a nice cheap unit that I have compared against a highly expensive Fluke 88 and found to match to within 10 mV.  That’s good enough for me!

On the procedure end of things, I first check the voltages and ripple with no load on the PSU at all. This is a quite unrealistic test and many PSUs do not appreciate it at all, but this Antec HCP-850 is specifically rated for zero load operation!

With that out of the way, I put successively higher loads on the PSU and check the voltages of the three main rails, all the way up to the PSU’s maximum output.

At the maximum output comes the last test, ripple at 95-100% load. This does assume that the PSU didn’t explode some time previously of course! I’d be quite surprised if the HCP-850 did, but it happens on lower end units sometimes.

The 12 V, 5 V and 3.3 V rails need to stay within 5% of their official value to stay within spec, closer is ideal of course. That means 12 V needs to be between 11.40-12.60 V, 5 V needs to be between 4.75-5.25 V and 3.3 V needs to be between 3.135-3.465 V.

Without further ado, we have the load tests ranging from 0w through ~846 W of load.

Quite good!  Not only were the voltages within spec at zero load, they were well within it at maximum load as well! The 3.3 V rail was the furthest from perfect, at 3.3% over spec, with 5 V at 2.8% and 12 V at 1.6%.  Not perfect, but quite good.

Despite sitting at full load for a good amount of time, the fan never made any noise to speak of. It’s a quiet character by nature and didn’t speed up much at all during testing. Similarly the exhaust air coming out the back of the unit was only slightly warmer than the ambient air. Antec did an excellent job on the efficiency of this unit.

Next up is ripple testing, and like I promised I’ll tell you what this “ripple” I speak of is first.
Ripple is a measurement of how far above and below the median voltage the voltage goes. To put it more simply, ripple is how much the voltage bounces around. All power supplies have some ripple due to their design, it is impossible to get rid of all of it, and very expensive to try. The more ripple in the voltage outputs the harder time components have making use of it, this is why almost every computer part out there has capacitors on it’s voltage inputs to smooth the ripple out. In the hunt for the worst of the ripple I check everywhere from 10 milliseconds per divider down to 0.5 microseconds per divider, and record the worst that I find. For all of the full load tests I have loaded the entire unit down to its full rated maximum, not just the rail I am checking.

The ATX specifications have a ripple spec as well of course, for the 12 V rail it is 120 mV, while for 5 v and 3.3 V it is 50 mV.

First lets look at 12 V, the first picture is at zero load and the second is at just shy of absolute maximum. In both pictures, each horizontal line represents 10 mV, in the first picture each vertical line is 20 microseconds, while in the second it is 10 microseconds. (As a side note, there are 1000 microseconds in a millisecond and 1000 milliseconds in a second.)

7 mV at zero load and around 40 mV at full load, very good! The full load ripple shot is a downright weird waveform, I’m going to be very interested to see what is inside this unit!

 Next, the 5 V rail. Zero load shot is 10 mV by 2 milliseconds, full load shot is 10 mV by 5 microseconds.

At zero load, the ripple is an excellent 9 mV; at full load, it is a much more interesting picture. The main waveform of the ripple is around 10 mV, but there are transients that reach around 35 mV. 35 mV is still within the 50 mV spec though, so it’s all good.

Last for ripple testing, 3.3 V! The zero load test is at 10 mV by 2 milliseconds, while full load is at 10 mV by 10 microseconds.

These full load shots are strange characters! The 3.3 V line was slightly worse than the 5 V, with ~11 mV at zero load and 40 mV including transients at full load. Still within spec, the Antec HCP-850 has passed both load testing and ripple testing, all that is left is to tear it apart and see what is inside!

Dissection & Component IDs

First, a disclaimer: Power supplies have dangerous voltages inside them, DO NOT OPEN POWER SUPPLIES. It’s just not a good idea, and could very well kill you. Don’t try this at home. Don’t try this at work. Just don’t do it.

With that out of the way, I’ll crack this thing open and we’ll see what is inside it. I think this is my favorite part of power supply reviews, really.

We’ll start with fan, it’s the first part out after all. In this case, it’s a pretty juicy unit with a 0.44 A maximum draw and PWM speed control.

Next up, a couple overview shots to get the lay of the land.

This is not a normal PSU folks. There’s only one heatsink in here! Generally, there is one to house the aPFC and main switches, and then a second packed full of schottky diode rectifiers for the output voltages.  This has the aPFC+switch heatsink, but no secondary. There’s also a rather excessive number of transformers and an odd orange wire wound character on the left there. Strange business, this!

Let’s follow the electrons through the unit and check out the components.

First there is the transient filter on the input, its job is to clean up the AC voltage coming into the unit. These come in three parts, X capacitors, Y capacitors, and inductors. The first set of them is on a PCB that you can see the bottom of in the left picture above.  Here it is from a couple more angles.

Six Y capacitors (little blue jobs, two on the receptacle itself, four on the PCB), two X capacitors (black boxy things) and two inductors, one of which is huge and wrapped in plastic for some reason. That is a solid transient filter right there, but Antec was only getting started! There is more on the main PCB that you can see in the pictures of the main PCB. On the main PCB, there are two more Y capacitors, yet another inductor, and a MOV for surge protection.

After the transient filter the AC is rectified into DC by a pair of LL15XB60 rectifiers, each rated at 15 A and 600 V. They’re bolted to a heatsink behind the (huge) aPFC inductor and next to a relay. “A relay?” you say? Well yes, the relay enables or disables the entire PSU other than the 5vsb circuit, this is how the HCP-850 gets under the 1 W standby maximum power draw limit of the EuP regulations.

Once through the transient filter and the rectifiers, the electrons cruise over to the aPFC section, where the voltage is increased to somewhere in the mid 300s and the electrons are stashed in the three large Rubycon capacitors. Following are pictures of the three 22N60N mosfets rated at 22 A and 600 V each, the B08G60C diode of unknown rating, and the label on one of the capacitors that make up the aPFC unit.

Rubycon is a well known high quality Japanese capacitor manufacturer, so you know that the three main storage caps aren’t going to cause you issues. As a side note, 350-400 V coming out of three 220 microfarad caps will really ruin your day if it nails you, this is why you don’t open power supplies.

At this point we run into the main switches, which send the electrons on their way through the transformers.  There are four 23NM60ND for that job, rated at 19.5 A and 650 V each.

As you can see, the mosfets are on the same heatsink as the aPFC mosfets and diode, and like them have both thermal pads and TIM between them and the heatsink.

Now, normally the electrons would head through the transformers and then be rectified by a stack of diodes on a secondary heatsink. As mentioned previously there is no such thing in this unit! Instead there is this strangely built transformer type thing on the top of the PCB, and six 031N06L mosfets on the bottom of the PCB! I have no real idea how this setup works, but it clearly works quite well.

You can see some posts coming through the PCB between the mosfets, those are the connections to the transformer in the left picture.  There’s a thick thermal pad that conducts the heat from the mosfets to the case of the PSU for cooling.

Now this unit is a DC-DC regulation unit for the 5 V and 3.3 V rails, that means the entire rating is first regulated to 12 V, and then the 5 V and 3.3 V rails are regulated off the 12 V rail. The result is much better efficiency, lower temps, and generally better regulation. The down side is more complexity and higher costs.

Below is the secondary PCB with the 5 V and 3.3 V regulation units on it. It has a sheet of metal over the front to keep the EMF from heading out through the rest of the unit and causing issues. Unfortunately for us, the plastic posts that hold the shield on aren’t possible to remove without breaking them, so I don’t know what parts were used.  There are some solid polymer capacitors in there however, which explains the nice ripple results.

The DC-DC regulation also explains a lot of the odd full load ripple results. Consider:  Every time one of the 5 V or 3.3 V mosfets fire it drops the 12 V rail slightly, so the 12 V mosfets fire sooner than they would have. Then, the 5 v or 3.3 V mosfet shuts off and the 12 V rail raises again, leaving the 12 V higher than it thought it would be, so it shuts down. Add to this that there are two secondary rails doing this thousands of times per second (around 66,000 timers per second for each secondary rail) and the 12 V rail has to be turning the mosfets on and off constantly anyway, and the 5 v and 3.3 V mosfets have to deal with the ripple already on the 12 V rail, and you can see why the main waveforms on all three rails are so fuzzy at full load. For bonus ripple fuzziness, the 12 V rails have both the variations in voltage from the main switches and from the secondary mosfets (whatever exactly their job might be), and you have a complicated operation!

Anyway, let’s move on and check out the soldering on this unit.

That my friends is some excellent soldering. I have yet to see better. If I felt like picking nits there are a couple leads that are a mm or two longer than perfect, but there isn’t anything nearby for them to short out on so it’s a rather inconsequential nit at best.

Now let’s look at the modular output daughterboard.

The soldering is excellent here, too. Better than my camera’s focusing skills certainly. That said, if you look closely at the mounting posts as they come through the PCB you’ll see a lack of a nut on them. Let’s look more closely.

Yup, just solder holding the mounting lugs in place. This is not good at best, and downright foolish at worst. I didn’t have any issues with them personally, but I’ve seen a few people break the solder on them taking the unit apart. Given that you shouldn’t be taking the unit apart in the first place that isn’t really an issue, but it’s possible that pushing too hard on the connectors could break the solder and lead to issues.

Oh well. Moving right along let’s look at the output filter for the main rails and make sure there actually are multiple rails in the first place. Quite a few lower end units claim multiple rails and don’t deliver them, but I’d be rather surprised if Antec didn’t make good on their multi-rail claim. If you look closely you can see three different sets of 12v wires headed to the modular output PCB, which goes a long way towards showing that multiple rails exist.

Lots of polymer capacitors and larger electrolytic capacitors here, as well as quite a few large post type inductors such as are used for current sensing in OCP protection. Yes folks, it really is a multiple rail design!

This concludes our tour of the insides of this Antec HCP-850 power supply. Next up, my final thoughts on it.

Final Thoughts & Conclusion

I went into this review hoping that I would find the Antec HCP-850 to be a glorious power supply of price point domination. The further into testing it I got the happier I became, as it just kept looking better and better. Perfection is hard to come by, but this unit does a mighty good job.

There are a few units of roughly this capacity that are 80+ Gold rated and have a lower price than the Antec HCP-850’s current price on NewEgg of $175 (down from $190). Only one is significantly cheaper, and it is from a dubious brand and doesn’t really count. Hence I would say the HCP-850 is a good value.

We’ll start off the conclusion with a list of PROS:

• Great looks, nice color and sleeving job.
• Nice long cables, and plenty of them.
• Excellent voltage regulation.
• 12 V ripple control is excellent.
• Very quiet fan indeed.
• Component choices almost excessive in their capacity.
• Good price/performance.

The universe likes perfection even less than it likes a vacuum, so there are cons as well:

• No nuts holding the modular output board’s mounting lugs in place.
• 5 V and 3.3 V ripple higher than I’d like, though still within spec.

I would rather like to know what the topology of this unit is, as it has me completely stumped.

Given all of the above, my sentiments on the Antec High Current Pro 850 W power supply are best summed up by one of the capacitors you may have noticed in the output filter, here’s a closeup:

Yes, happy capacitor is happy, and I am too. Not only did the HCP-850 fulfill my expectations it bested them almost across the board. This is my new 24/7 power supply, which should tell you a lot.

In conclusion, the Antec HCP-850 power supply is quite worthy of the Overclockers.com Approved stamp!

– Ed Smith (Bobnova)