Zalman 850W Heatpipe Cooled PSU - ZM850-HP Features and Specs

Article Index
Zalman 850W Heatpipe Cooled PSU
ZM850-HP Features and Specs
ZM850-HP Cables and Inside
Test Setup, Methods and Testing
650W Load Test and Final Thoughts

Features & Specs:

Zalman is more known for its cooling products than for its Power Supplies, but with their products now reaching 850W, they are starting to get seriously noticed by the enthusiast community.  While they don't yet have the same reputation as Antec or Enermax, they are building a reputation that should take them into the cases of many computer gamers in the near future.  Below is a list of the features of this unit according to Zalman.

Dual Heatpipes Installed for Maximum Cooling Performance and Ultra-Quiet Operation
Dual heatpipes with ultra-high cooling performance incorporated on the main heat sources enable high load operation even at low fan RPM for a dramatic reduction in noise levels.

Improved Power Factor & Reduced Harmonics through Active PFC
By implementing Active PFC(Power Factor Correction), the Power Factor (PF) is improved up to 99% while harmful harmonic frequencies are reduced to meet the Line Harmonic Distortion Requirement of IEC61000-3-2 Class D Specification.

High Efficiency Design and 80 PLUS Certified
This power supply is capable of reaching a maximum of 86% efficiency (230VAC, Full & Typical Load) through its use of high switching frequency and low power-loss circuitry. This product has been certified with the 80 PLUS Power Supply Certification and guarantees a higher efficiency compared to uncertified products.
* 80 PLUS is an innovative, electric utility-funded incentive program that strives to integrate more energy efficient power supplies into desktop computers and servers.

ATX20+4 Pin Main Connector
ATX20+4 Pin Main Connector broadens the range of motherboard compatibility.

Supports ATX12V CPU 4-Pin and EPS12V CPU 8-Pin
Two ATX12V CPU 2 2 (4-Pin) power cables can be combined to form an EPS12V CPU 8-Pin power cable.

Four PCI Express VGA Power 6-Pin & 6+2 Pin Connectors
Four independent 6-Pin Power Connectors (two 6-pin & two 6+2 pin) provide support for Nvidia’s Quad SLI.

Module Cables
Modular cables provide organized cable management and improved air circulation inside the computer case.

Ultra Quiet 140mm Fan
The ultra quiet 2 ball-bearing 140mm fan maximizes the airflow and minimizes the noise level enabling a noiseless computing environment with optimized cooling.

Standby Noise Filter Switch
The 5Vsb Noise Filter eliminates high frequency noise in standby mode.
* The Standby Noise Filter Switch is NOT a power switch. The AC Power Cord MUST be unplugged in order to turn the power supply OFF.

Six Independent +12VDC Outputs
Six +12VDC rails supply power independently to the CPU, VGA, motherboard, and peripheral components for the highest level of stability and performance.

EZ Grip Connectors for ODDs & HDDs
EZ Grip Connectors for easy removal of the plugs from ODDs & HDDs.

Gold-Plated Terminals & 16AWG Wires
All connector terminals are gold-plated to minimize contact resistance and power lose.
16AWG (thicker than 18AWG) wires are incorporated to minimize voltage drop during high load operation.

Sleeved Cables
All power cables are sleeved for easy cable management and improved air circulation inside the computer case.

Multiple Safety Features
Over-Voltage Protection, Over-Current Protection, Short-Circuit Protection, Under-Voltage Protection, Over-Temperature Protection.

Complies with WEEE & RoHS environmental directives of the European Union.


Not only does this PSU have a decent list of features, according to the label, it has enough wattage to power almost every computer around.

Zalman Label
Zalman Label


More detailed information in the chart below.

Electrical & Physical Characteristics
AC Input Range
100VAC ~ 240VAC ±10% DC Output
Frequency 47Hz~63Hz ZM850-HP
AC Input Current
115VAC 12A Output V. Output Load
230VAC 6.3A Imin Imax Ipeak
PFC Type Active PFC +3.3V 0.8A 25A 35A 191W 850W
Power Factor 99% Maximum
+5V 0.5A 30A 35A
Inrush Current
Limit (@ Cold start at 25°C)
115VAC 60A
+12V1 0.5A 18A 22A 768W
230VAC 100A +12V2 0.5A 18A 22A
Efficiency 86% Maximum @230VAC, Full&Typical load
+12V3 0.5A 28A 30A
DC Output
Output V. Regulation Range
At Full
+12V4 0.5A 28A 30A
+3.3V ±5% +3.14V~+3.47V
+12V5 0.5A 18A 22A
+5V ±5% +4.75V~+5.25V +12V6 0.5A 18A 22A
+12V1 ±5% +11.4V~+12.6V -12V 0.0A 0.8A
+12V2 ±5% +11.4V~+12.6V +5VSB
0.1A 3.5A 4A
+12V3 ±5% +11.4V~+12.6V Protection Features
+12V4 ±5% +11.4V~+12.6V Over Voltage Protection(OVP)
+12V5 ±5% +11.4V~+12.6V Over Current Protection(OCP)
+12V6 ±5% +11.4V~+12.6V Short Circuit Protection(SCP)
-12V ±10% -10.8V~-13V Over Temperature Protection(OTP)
+5VSB ±5% +4.75V~+5.25V Under Voltage Protection(UVP)
DC Output
& Noise
Output V. Specification At Full
Ambient Temperature
+3.3V 50mV Operation 0°C ~ +50°C
+5V 50mV Storage -20°C ~ +80°C
+12V1&2 120mV Ambient Humidily
+12V3&4 120mV Operation 5%RH ~ 95%RH
+12V5&6 120mV Storage 5%RH ~ 95%RH
-12V 120mV Dimensions
+5VSB 50mV 210(L) X 150(W) X 86(H) mm

If you were paying attention, you'll notice a discrepancy between the label on the PSU and the chart above.  According to the chart 12v3 and 12v4 are rated at 28A while 12v1, 12v2, 12v5 and 12v6 are rated at 18A.  The PSU states that each of the 6 +12v rails is 18A. 

We'll take a look at the cables and tear into this unit on the next page.