Zalman ZM600-HP Heatpipe Cooled PSU


Product: Zalman ZM600-HP PSU
Provided By: ZalmanUSA
Price: ~ $154 CDN Online


Today's hardware requires a lot more power than in the past.  When I picked up my first 350W PSU, many people I knew thought I was a little extreme because that was ridiculously overpowered for the day.  It powered an Athlon T-Bird 1GHz, a GeForce 2MX, a 40GB Hard Drive and a 12x LiteOn CDRW.  That was a pretty decent system for the day, and a 350W unit was a little on the large side.  My how times have changed!  The only systems that ship with 350W power supplies these days belong to Dell, HP or Acer, and are super value systems.  For the enthusiast market we see 500W minimum requirements and often see 700W + on high end systems.

ZM600-HP - Box
ZM600-HP - Box

Today we are looking at the latest power supply from Zalman - the ZM600-HP to see if their 600W Modular unit has enough power for most people.  We will take a look at performance, functionality and the features of this unit to find out if it offers what you need to keep you running stable.

Bundle & First Look:

Many power supplies today are modular, and Zalman follows this example for the most part.  The ZM600-HP is not complete modular as the main power leads are hardwired into the unit and are not removable.  The additional power connectors are modular however.

Bundle Of Cables
Bundle Of Cables

Included in the bundle of cables pictured above are actually seven individual leads that provide 7 Molex, 2 Floppy, 6 SATA, CPU #2 Power, and PCIe #2 connections.  This unit has more connections that many power supplies out there and promises stable power with its four +12v rails.

PSU Back / Label
 PSU Back / Label

PSU Back / Bottom
 PSU Back / Bottom

The ZM600-HP uses a nice large 120mm fan that always spun very slowly during testing and was inaudible no matter how much we connected to the system.  The back of the PSU has a very open honeycomb mesh that allows unrestricted airflow and gives us a peek at the heatpipe cooler inside.

On the next page we'll take a closer look at the modular connectors and take a peek inside.

Closer Look:

Modular power supplies are all the rage right now - and rightly so.  They offer convenience and less cable clutter as you connect only the cables that you need.  The picture below shows off all the connectors, many of which are somewhat proprietary to Zalman PSU's; unlike OCZ which uses standard Molex or PCIe ends on the PSU side.

Modular Connections
Modular Connections

Below is a diagram taken from Zalman's site to show how everything hooks up to this unit.  Click the image for a larger picture.

Lead Diagram
Lead Diagram

If you want to open the PSU and see what is inside, you will void your warranty, so we did it for you.  It requires the simple removal of four screws and you're in.  As you can see below, there really isn't a whole lot going on inside the PSU.  Although the components seem to be quiet small, keep in mind that most of the bulk inside a power supply is heatsinks.  Because the ZM600-HP uses a heatpipe cooler, the voltage regulators don't have massive heatsinks strapped to them.

Inside View
 Inside View

HeatPipe Cooler
 HeatPipe Cooler

It does look pretty empty inside and in a few minutes we'll take a look and see how well it can regulate voltage.

Specs & Rails:

Many companies rate their voltage regulation at 5% - 10% and Zalman falls right in with the rest of them.  Their +12v rails are rated at 5% tolerance with the -12v rail rated at 10% tolerance.  Check out more details below.


As you can see above, the PSU has four +12v rails, but what does each rail power?  We did a bit of searching and have posted up the results for you in a little table below.

+12v Rails

In my opinion the rails are split perfectly.  Each PCIe connector runs on its independent rail and this is key to stability with SLI or Crossfire systems.  All of the drives are on a rail together and the CPU and motherboard connector are on their own rail.  If these rails deliver solid voltage at +12v or above, we could assume that it would be a great component for an overclockers computer.

Check out our test system, and actual voltage measurements on the next page.

Test System:

Our test system is listed below:


We ran three sets of voltage measurements on this power supply.  The first measurement was taken with the PSU plugged into the CaseBuy EZ PSU Tester 3.  The second measurement was taken with the system running idle at stock speeds.  The final measurement was taken with the system running fully loaded and overclocked.  Voltage and load measurements were taken with a multimeter - not with a software monitoring program.

The PSU load was 2W when empty and the PSU ran at 23C - only a couple of degrees warmer than room temperature.  When running at stock speed idle, the system drew a total of 180W and the PSU heated up to 36C.  When overclocked and running at full system load we only managed to draw 276W out of the PSU at a temperature of 37.5C.

With a overclocked Core 2 Duo CPU, overclocked 7950GX2 graphics card, and running a ton of applications including hard drive transfers, games and more we couldn't bring our system load up to half of what this PSU is rated.  Certainly it will be powerful enough for most systems.  That being said, how are the voltage levels?

Click for full-sized chart.
Click for full-sized chart

No matter what kind of a load we put on the PSU, we couldn't bring it over 300W in our test system.  This system is no slouch when overclocked either so the results kind of surprised me.  I thought we'd be able to draw more power and perhaps cause the rails to drop a little.  Apparently I was wrong.  The 12v rails are a little higher than 12v and never drop off more than 0.05v.  The 3.3v line fluctuates the most as it drops from 3.45v (no load) to 3.34v idle and remains rock solid when loaded.


The Zalman ZM600-HP has been rock solid throughout testing.  Since we installed it, it's been running our test system overclocked at 100% CPU load most of the time.  It has never wavered at all.  The voltage on the +12v rails is solid and is about .5 volts high - even when we are drawing as much power as we can.  If you have a high-performance system that you want to keep quiet, the ZM600-HP is a worthy choice.  If you have an extreme system that includes a couple of 8800GTX cards in SLI, and 8 or more drives running a Quad Core CPU, you may have to invest in a more powerful unit, but we can't even make this one sweat.  All-in-all, it's a top performer.


  • Modular design helps reduce cable clutter.
  • Active PFC is efficient.
  • Large, slow & quiet 120mm fan.
  • Heatpipe cooler in PSU!!
  • Blue LED inside adds bling!
  • Solid, stable power on four +12v rails.


  • None. Rating
Software Pack:
Total Score 9.8


I'd like to thank ZalmanUSA for sending this PSU over for us to review.

If you have any comments or questions, please feel free to drop us a line in the forum at the "Comments" link below.