Testing:

Load Testing was done utilizing 2 hour stress testing sessions using programs like Prime95 and intense 3D games including BioShock, FEAR and Half Life 2: Episode 2. Idle testing was allowing to system to idle at room temperature for at least 30mins.

Test Platform:

• ASUS Striker Extreme

• Intel E6600 Core 2 Duo

• Dual Nvidia 8800GTS's

• 2x Western Digital 160GB HDD's

• 2x1GB Kingston HyperX DDR2

• Sony 16x DVD-RW

Idle

Load

   Voltage readings were very solid with very little fluctuation during testing. Of course these are just snapshots of a couple seconds during hours of testing, but you get the picture. Stable lines and stable voltage is what you'll get with the ZM850-HP.

Efficiency Testing:

  Efficiency testing was done using my trusty Seasonic power angel. It will test the Power Factor of this unit. What that means is it will tell us exactly how much of the power drawn from your wall socket is actually being used. The higher the percentage of the PFC, the better. Let's take a look at the whole scope of recent power supply reviews.

 

Conclusion:

   Here we come to the end of the review where I leave all this information in your hands to make your own decisions as to what you see and what your own needs are. It's impossible to sum up this particular power supply in one word as I've done on some units in the past. The major reason I'm not jumping up and down screaming "GO BUY IT NOW!" is for one simple factor; the lack of an on/off power switch. I can't even begin to guess as to why Zalman left out this truly necessary feature on an enthusiast power supply in the current market. I know overclockers and upgraders alike will frown on a power supply without a dedicated on/off switch. Why? Quite simply; convenience. In order to completely power off this power supply you'll need to physically pull the plug! This isn't 1996 and by now every power supply, cheap or high end should have the power switch. Period.

   Now as much as the lack of the power switch bothers me, I can't let it outshine the rest of the unit totally. It's a fantastic power supply with tons of power and tons of cables and cable options. It's built with Zalman quality and the unique dual heatpipe cooling design is peace of mind that even if your power supplies fan died the heatpipes will "probably" keep your PSU from dying a quick a painful death providing you've got airflow in your case.

   I still don't understand the "standby noise filter" switch and I think it's completely useless. They should've used the money spent on that switch and turned it into a dedicated power switch. Overall however this power supply is a great quality unit with only one minor flaw. But that one flaw is keeping me from giving it an editors choice award.

   The price is not cheap but that's to be expected in this market segment of brand name and high power units. At a going rate of around $235  for the ZM850-HP over at Acoustic PC, there's certainly lots to choose from in this price range, but if you want one of the best names in the business, you'll need to pay top dollar for it.

   This Zalman ZM850-HP was absolutely silent and I didn't notice any vibrations at all. However if you need a powerhouse power supply like this and you're somehow running (or trying to run) and super silent and vibration free system, you can always add one of these to your order. It'll further absorb any unwanted vibrations. I've used one on lots of cases and they do what they say they do.

   I'd like to send a thanks to Acoustic PC for sending out this unit for review. If you're looking for just about anything for quiet cooling for your computer, be sure to check them out. It's what they do!

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