CoolMax RM-750 750 Watt Power Supply

Coolmax Technology, Inc. is a rapidly growing company that was founded in the year 1997. Our initial task of providing cooling solutions for electrical and industrial applications using AC and DC voltage fans is our solid foundation. Our commitment to excellence in both products and service had earned for us the reputation as a leading thermal solutions provider in the industry. We strive to work hard, hand in hand with our clients, from the biggest to the smallest. They rely on our company's ability to provide quick and professional responses to inquiries and production demands. Our factories are located in China and are ISO9000 and 14001 certified, all our products are UL, TUV, CSA, CE approved. Coolmax is dedicated to providing the best cooling solutions engineered for a high-tech world while maintaining long-term customer relationships. Source: Coolmaxusa.com 

CoolMax is a new name in the power supply market.  Their monstrous 1350 Watt power supply has won many awards and has high praise, but their lower models of power supplies seem to be of a lower quality.  This is my second time reviewing a CoolMax product, so lets see how it performs and what is included in the box.  Today, we are taking a look at the RM series from CoolMax.  The RM series appears to be the 'value' line up for CoolMax.  This particular model is the RM-750, has a 750 watt power rating. 

Upon opening the box, you will find the only screws, and a power cable.  No manual was found in the box, This RM-750 being a retail version of the unit, is not good. However, there is some information about this power supply on the box. *Update: The manual can be found on the CoolMax website.

Here are some of the main features and specifications from CoolMax's Website:

The Power Supply:

The power supply features a matte black colored housing, which looks pretty standard these days.

Looking at the side of the power supply, there is a CoolMax label with their logo on it, the model number and a condensed specification list.  Note that there are three +12v rails with the +12v1 supplying up to 19 Amps and the +12v2 and +12v3 supplying up to 18 Amps each, which is good for peripherals requiring more power such as a multi-core CPU and/or multiple graphics cards.

There is an large grill on the back which allows the 120mm fan to exhaust hot air, an on/off switch and AC Power Input.  This power supply does feature Active PFC, as noted by the sticker, so there is no need for a  switch to select the input voltage.  There is also a fan speed switch which allows the user to change fan speeds (which is unusual and is rare in newer power supplies).  The available options are: Low, Automatic and High.  I prefer to just leave it on automatic.

This power supply features the following cables:

-A 24-pin ATX power connector with removable 4 pin for backwards 20-pin compatibility.

-A 4+4 pin (8-pin) +12v EPS Power Connector 

-2x 6 Pin PCI Express Power Connectors.

-8x Molex Power Connectors which have a grip for easy removal from devices.

-4x Serial ATA Power Connectors

-2x Floppy Power Connectors

Cooling:

There is a 120mm fan on the bottom of this power supply. During testing, at idle loads, this fan is quiet, which is great for a 750 Watt power supply.  With loads, the fan slowly sped up to what I would call a medium-high speed, which was audible.  The fan speed switch was interesting.  When the fan was at a higher speed, switching it to low caused the fan to stay stuck at a low speed, which could potentially overheat the power supply.  High speed was just too loud and caused the fan to vibrate and rattle.  Automatic mode is highly recommended.

Inside the Power Supply:

* Taking this power supply apart will void the warranty.

Inside the power supply, there are two large black finned heat sinks that offer a dense amount of fins to cool down the voltage rectifiers. There is a large transformer in the middle and a tiny one underneath it.  The layout and build quality of this power supply is acceptable. The Primary capacitor is Teapo branded.

The Primary capacitor is Teapo branded.

The secondary capacitors are also Teapo branded.

The fan inside is a Cool Max / Globe Fan branded fan. It has the model number B1201512H with a maximum draw of .38 AMPs.  An interesting blade design is used.

Testing:

For this power supply, the test system consists of the following:

-Antec Nine Hundred Case

-Intel Core 2 Quad Q6600 Quad Core Processor @ 3.4 GHz

-ZeroTherm Nirvana 120 Heatsink

-eVGA nForce 680i SLi Motherboard

-2GB (1GB x 2) of Mushkin XP2-8500 DDRII-1066 Memory

-320GB x 4 Western Digital 16MB Cache Hard Drives

-2x nVIDIA GeForce 8800GTS (G92) Video Cards @ 715MHz Core / 1000 MHz Memory

-Sound Blaster Live! 5.1 Digital Sound Card

-Sony 16x DVD-RAM / 18x Samsung DVD-RAM Drives

-4x 120MM fans, 1x 200mm fan

-2x CCFL Lights

(Multimeter Results)

*For additional / larger pictures of the CoolMax RM-750, Click Here

*Voltages are at 'Max Load', running Orthos, SiSoft 2009 Hard Drive Benchmark and 3DMark06 CPU Test 1 and 2 / Deep Freeze HDR test, and read with a Multi-Meter.

Capacitor Brands:

Good, Taiwanese manufactured capacitors. 

Primary: Teapo

Secondary: Teapo

Voltage Results:

+The results were great for this power supply and are within range.

Stability Results:

+Everything ran fine during testing, the system was stable and performed the tests as expected. 

Fan Speed Impressions:

- This power supply features a switch for changing the fan speeds.  Automatic is best.  High speed is just too loud and causes the power supply fan and chassis to vibrate.  Low speed can damage the power supply, when it is under heavy load.

Installation:

+Installation of this power supply went well.  No issues fitting inside the test system's case.

Conclusion:

This power supply would be ideal for anyone looking to build a multi core system with multiple video cards. A few things what disappointed me was the lack of a physical manual, the vibrating fan issue and the lack of SATA connectors.  At around $90, this power supply is a bit high for a value 750 Watt PSU.  Overall, this is a good power supply and should be purchased by anyone looking for a decent performing power supply at a reasonable price.

Pros +

-Good power output

-Three year warranty

-Quiet fan when automatic mode is selected

Cons -

-Fan is loud on the high speed setting

-Fan speed switch is not really needed these days

-Cables are not modular

-No physical manual

-Lack of SATA connectors (4)

Techaddicts.net would like to give this power supply a 'Good' rating.  It needs some improvement, just like the CUG-950B.

Home