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- Date:
- Wednesday, May 27, 2009
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
Corsair HX850W Power Supply
Another week and another company coming in trying to show authority in what is probably the hardest PSU segment to hit a home run in; the 850 watt computer power supply. One has performed great, a few have done OK; where does Corsair fit into the mix?
Build Quality
The Corsair HX850W features a single 140mm fan design. 140mm fans are in the same vein as 120mm fans in that they can provide for quiet cooling environments due to the ability to move a larger volume of air at slower speeds than a smaller diameter fan. The 140mm fan is the almost the largest diameter fan we are likely to see in ATX power supplies given the physical constraints of the form factor. While great for quiet computing environments, the key criteria in our evaluation is whether or not the cooling solution is sufficient; not necessarily its sound level or form factor.
Externally the Corsair HX850W is once more almost identical to every other Corsair unit we have reviewed to date. The top of the unit is dominated by the large 140mm fan, and the rear is mostly clear as the unit is well perforated to allow air to vent. The finish is the same tough textured black powder coat-like(?
that we have come to know and love as it is smart looking while being heavy duty and resistant to scratching.
The unit features a semi-modular cable design, like the HX1000W, with all the cables being well sleeved. Indeed, for once CWT has seemed to be able to sleeve the cabling into the unit’s housing so that they no longer look unfinished or give you maintenance issues down the road. Why this took so long to figure out when Seasonic, Andyson, Enermax, SuperFlower, and just about everyone else had figured it out is unclear. And we have bitched loudly about this before. Hopefully HardOCP’s whining continually like a loft full of unsatisfied sorority bitches has had some impact. Because, yes, we whined repeatedly and loudly…and not into our pillows. Even though it is somewhat low level complaining that is likely off the radar, it is an important thing that you be aware the condition of your main ATX and EPS leads as you move your PSU into your third or fourth system build and recognize just how well maintained the most important leads are exactly where these exit the PSU case. The fact is that when you spend this much money on a big-wattage PSU, it is likely to be with you for a while and having sheaths flow into the body of the PSU are actually a big deal.
(Kyle thoughts: I used to not be in this camp and simply gave Paul room to bitch. But as I have paid attention to multi-chassis builds with high-end Corsair PSUs and other around the offices here, I have to say that Paul has been dead on with all of his "whining" all this time. He simply wants to make sure our readers get a PSU that is worthy of the long term warranty they purchased. )
The HX850W comes in at a length of 7 1/8 inches while the cables provide a serviceable length of ~18 inches to the first (or only) connector and are sheathed in black mesh. This makes this unit almost a full inch longer than theTX850W. However as stated above, this unit's sleeving is complete on this unit so that is certainly a nice change from previous units.
Internal Build Quality
Once we open the Corsair HX850W we find ourselves looking at surprisingly NOT another CWT PSH power supply. Indeed, this unit looks to be one of CWT's new "DSG" models. From the top here the topology does not look radically different on the primary from the PSH series, however the components are oriented differently and the unit is now sporting a pair of primary capacitors. The heatsinks used in this design are much thinner, and bar like, than what we have seen previously in CWT built units of this capacity, however the amount of waste heat being dissipated will also be much lower if the efficiency numbers being advertised by Corsair are correct. (Better efficiency equals less waste equals less heat from the PSU itself.) The HX850W, like the TX850W, uses a Yate Loon fan rated at 0.70A at 12v to cool the unit.
As we said above, the primary power components seem to be arranged in the same topology however the actual primary layout has been modified significantly. Besides the APFC components all shuffling around in location, with the add-in PCB no longer hugging the primary capacitors, the primary capacitor has multiplied in this new unit to be capacitors supplied by Nippon Chemi-con and rated at 420v 390uF 105c.
Before moving directly to the secondary, we notice that the unit has a single 12v transformer along with the +5VSB and a number of optocouplers in the center of the unit. The reason for the single 12v transformer is that once we look at the secondary we see that this new CWT design uses synchronous rectification for the 12v output and DC-DC VRM's for the minor rails. Each minor rail is supplied by one of the PCB's housed next to the big torroid coil which is for the 12v output. The capacitors filling out the secondary are all Nippon Chemi-con as well, including the solid polymer capacitors, making this an all around Nippon Chemi-con affair that is tough as dual-weilded Desert Eagles in the hands of a hot chick. (Liberals Don’t Look You Will Be Offended! Unless you like women more than you dislikes guns in the hands of US Citizens. Or maybe not.) More for your viewing pleasure, here, here, here, and here. And one more here for those that want to see her with a weapon that can kill you from 400 yards away. (Yes she has traned hard! Please be nice to her in the forum thread as she is my wife but like any woman, she loves to be the center of attention, especially with HardOCP readers because she knows you guys are the shit when it comes to hardware. . .scratch that "[H]ardware." Yeah I know I am a day or two late, but let it be known that we greatly appreciate all the service people that keep us safe at night.) The wiring that leads to the modular PCB is all routed well and the PCB itself is very clean which gives us a better overall feeling of construction than some of the 850 watt units we have seen in the past. Lastly, we see that on the PCB, that Corsair has gotten these units screened with their own model number as opposed to the CWT base model number. This would lead us to believe the many of the changes seen here today will likely be "Corsair-only" in the near future.
Build Quality Summary
Overall the build quality of the Corsair HX850W is in many ways similar to other CWT built Corsair units, but in this case the new topology is a significant advancement over the older independently regulated design of the CWT PSH model that was used in the TX850W. The exterior of the unit is almost identical to other Corsair units in fit and finish while recycling the color scheme of the HX1000W and would leave you to believe they are one in the same via "HX" branding when this just-released PSU is actually a new unit. The one change of note here that we have begging for is that this new CWT design actually sleeves the cables all the way into the housing which is a welcome improvement and a tremendous win for the enthusiast that will find himself using this PSU for multiple builds over the next few years. Start cranking hard on those ATX and EPS leads and you will see quickly what we are talking about.
Once we move inside the changes are more pronounced as this unit uses a slightly rearranged, but topologically similar, primary design. The secondary design, however, is all new for this power output range; Corsair uses synchronous rectification for the 12v rails and DC-DC VRM's for the minor rails. Lastly, the capacitor selection is fully Nippon Chemi-con including both the standard electrolytics and the solid capacitors which is something we are extremely happy about. All this adds up to make the HX850W PSU the best built Corsair power supply to date.