Cooler Master Silent Pro M2 1000 W

Introduction

We would like to thank Cooler Master for supplying the review sample.

Cooler Master's Silent Pro M series has been around for a long time and it was time for a fresh series to take over, so the M2 was released as replacement. Currently the Silent Pro M2 ranks third in CM's PSU series portfolio, below Silent Pro Hybrid and Silent Pro Gold. The most noteworthy difference of M2, in characteristics, to the two aforementioned series is the efficiency certification which dropped to silver and bronze levels in order to retain lower prices.

The new M2 units come in six flavors with capacities ranging from 420W to 1000W. The two stronger units with 1000W and 850W have Silver efficiency while all others are Bronze. Here we should note that at the time of the review no member of the M2 series was officially certified but we are pretty sure that this is just a matter of time.

Today's review subject is the Silent Pro M2 1000W which like all other M2 units uses a semi-modular cabling system, features a single +12V rail and it is made by Enhance Electronics, the same OEM that also manufactures the Silent Pro Hybrid and Gold units for CM. The M2 1000W is also equipped with a 135mm HDB (Hydro Dynamic Bearing) fan, according to CM, which besides silence promises long lifespan compared to a plain sleeve bearing one. Finally the warranty is set at five years, providing long peace of mind to the future buyers.

Specifications

Cooler Master RS-A00-SPM2 Features & Specs
Max. DC Output	1000W
PFC	Active PFC
Efficiency	80 PLUS Silver
Operating temperature	0°C - 40°C
Protections	Over Voltage Protection Under Voltage Protection Over Current Protection Over Power Protection Over Temperature Protection Short Circuit Protection
Cooling	135 mm Hysint Bearing Fan (DFS132512M )
Dimensions	150 mm (W) x 86 mm (H) x 180 mm (D)
Weight	2.4 kg
Compliance	ATX12V v2.3
Warranty	5 years
Price at time of review (exc. VAT)	$199.99 (MSRP)

According to CM efficiency is 80 Plus Silver but at least at the time of the review the 80 Plus organization hadn't evaluated this unit. Unfortunately, as Enhance the OEM of this unit uses to do, the max operational temperature reaches only 40°C so it is 10°C lower than what ATX spec recommends (not requires). Thankfully the unit is equipped with all protections including OTP so if its internal temperature goes high it will shut down to prevent damage. The cooling fan according to CM is equipped with a Hydraulic Dynamic Bearing which ensures a longer lifespan along with quiet operation. However when looking up the fan's specific model number (DFS132512M) the original manufacturer, Young Lin Tech, states that this fan uses a plain sleeve bearing. To clarify this we fully disassembled the fan and shed lots of light on this matter. More about this on the corresponding page of this review (A Look Inside).

The dimensions are the standard ones for a PSU with 1kW capacity and the weight is increased thanks to the large heatsinks that Enhance uses. Finally the warranty is set at five years, showing CM's confidence in this product and unfortunatelly the MSRP is on the high side.

Cooler Master RS-A00-SPM2 Power Specs
Rail	3.3V	5V	12V	5VSB	-12V
Max. Power	30A	30A	80A	3A	0.3A
	180W		960W	15W	3.6W
Total Max. Power	1000W

Let's startwith the minor rails. These are pretty strong at 180W combined, a power level that most likely no contemporary PC system will take advantage of. On the contrary the +12V rail, which is mostly used nowadays by almost every component, needs high power to cope with power hungry systems and in this case it can deliver up to 80A in a single rail so it won't run into any problems, even with high-end VGAs, CPUs etc. Finally the 5VSB rail with 15W total capacity has 2.5W more power than the minimum seen in modern PSUs. We would highly prefer though, to have 20W or more power.

Cables & Connectors, Power Distribution

Native Cables
ATX connector (560mm)	24 pin
8 pin EPS12V (620mm)	2
Modular Cables
8 pin PCIe (610mm) / 6+2 pin PCIe(+100mm)	3/3
SATA (410mm+100mm+100mm+100mm)	12
4 pin Molex (410mm+100mm+100mm)	3
4 pin Molex (410mm+100mm) / FDD(+100mm)	2 / 1

As you can see the fixed cables are very few whereas the number of the modular ones is large enough, something very convenient. Of course all fixed cables are fully sleeved while the modular ones are flat (ribbon cables). The unit has a sufficient number of connectors and strangely enough isn't equipped with any 4+4 pin EPS12V connectors but instead both are two 8pin ones. Also the main ATX connector is a 24pin type and not 20+4pin, as most PSUs use. Apparently CM wanted to cut any ties with the past. Also cable length is adequate but the distance among connectors is too short at mere 100mm while the ATX spec recommends 150mm. Most likely this won't be a problem for the PCIe connectors, since usually they are connected in pairs on the power sockets of the VGAs with small distance between them and probably for SATA connectors, but for the 4pin Molex ones this could be an issue. Finally the 24pin ATX connector, the two EPS and all PCIe ones use 16AWG wires while all other connectors use 18AWG.

Since this PSU features a single +12V rail we do not have anything to comment about its power distribution.

Packaging

The packaging is rather large and features nice graphics along with a matching combination of purple and white colors. In the front, right corner we find the 80 Plus Silver badge along with the five year warranty logo while underneath there is a small text describing the copper-aluminium heatsinks used in the internals, the modular cabling system and the HDB fan. A small photo of the unit along with the capacity description can be found in the front, bottom left, corner. On the rear side the most important info is depicted on two charts showing the fan and the efficiency curves. Finally, the specifications of the M2 1000W and its power distribution table can be found on one of the box's sides.

Contents

Once we opened the flap a not so thick piece of packing foam greeted us. The PSU is located under it and is stored in a plastic bag. Additional pieces of packing foam are located all around the unit providing efficient protection even for worst case scenarios (delivery persons playing football with the boxes). The bundle includes a user manual, a warranty card, a set of fixing bolts, an AC power cord and the necessary modular cables. Unfortunately neither a storage pouch for the cables neither some zip ties are included.

Exterior

CM's products enjoy a nice style/design in general and the M2 1000W is not an exception to this rule, of course. The side decals cover all of the side areas and while they do not feature fancy graphics their quality is exceptional. The large power specifications label is located on the bottom side so it won't pose a problem to the modders who want to show off the PSU through the side panel window. On the front a honeycomb design exhaust grill is used and a sturdy On/Off switch is installed beneath the AC receptacle. On the rear side the modular panel includes three sockets for the equivalent PCIe wires (each one includes two connectors) and five peripheral sockets. The fixed wires are only three and fully sleeved back into the housing and there is a grommet around the cable exit hole. The fan grill utilizes the usual design but it features a nice CM logo in its center, making it more attractive. In general the external looks of the unit indicates a high quality product and hopefully the internals will offer the same impression, too.

A Look Inside

Before reading this page we strongly suggest to take a look at this article, which will help you understand the internal components of a PSU much better.

The OEM of this unit is Enhance Electronics and this is made quite obvious by the huge heatsinks with the extra long fins and mainly from the pair of black and white wires that feed the PCB with AC power. Usually these wires are brown and blue but Enhance has its own color codes, as it seems. The platform of this unit has many differences compared to the one of the Silent Pro Hybrid 1050W PSU and this is natural since the latter has Gold efficiency and is more expensive. To provide you a clear view of the internals we removed the two APFC caps and the secondary heatsink which fought well but eventually the Hakko 808 prevailed. These Enhance heatsinks are a real pain to remove and on top of that they totally block the view.

The first part of the transient filtering stage as usual starts right at the AC receptacle. In this case we found two X caps along with a pair of Y ones. Also the power cables are wrapped around a ferrite bead and the same applies to the grounding wire which is wrapped around a smaller ferrite bead. The second part of the transient filtering stage is located on the main PCB and includes two CM chokes, two pairs of X and Y caps and an MOV. Also next to the right CM choke resides a huge thermistor, for protection against large inrush currents and a little further there is a relay which cuts it off from the circuit once the start up phase finishes. This way it provides a small efficiency boost and the most important it allows the thermistor to cool down.

The two parallel bridge rectifiers are cooled by the primary heatsink and a smaller one. On the PCB there is room for a third bridge, for even more power.

Moving on to the APFC, we find a large PFC choke and in front of it the PFC input capacitor resides. This cap filters the high frequency ripple of the fully rectified signal, which derives from the output of the bridge rectifiers. The APFC uses two IPW60R099CP fets and an STTH15R06D boost diode. The hold up caps are two parallel Matsushita/Panasonic (390μF, 420V, 105°C).

This unit uses a two power switch Active Clamp Reset Forward (ACRF) topology to achieve higher efficiency. Recently Enhance heavily uses this topology in all of their higher efficiency PSUs, since it is cheap to implement and provides loss-less switching thus minimized energy dissipation. However it has a small issue with ripple suppression, at least in our experience. The primary choppers are two IPW60R099CP fets and the reset switch is an FQPF3N80C fet.

In the secondary side synchronous design is used and the presence of only two toroidal chokes means that a type of group regulation design is used for the generation of the main rails (12V, 5V and 3.3V). The +12V rail regulate four IPP041N04N while the minor rails handle two pairs of AP72T03GP. In the secondary heatsink the 5VSB SBR (MBR1060) is also bolted. This SBR can handle up to 10A so it will easily deliver the full power (3A) of this rail. Finally notice the copper plates on which all fets are installed. These provide better thermal conductivity than aluminium but the latter provides higher heat release and it is of course much cheaper than copper.

Almost all filtering caps used in the secondary are provided by Teapo and are rated at 105°C. Only the 5VSB converter is an exception to the above since it uses a Nippon Chemi-Con cap.

On the front of the modular PCB there are lots of small Teapo caps, which are used for extra filtering of the DC outputs from AC ripple. There is also a much larger Nippon filtering cap. On the rear side, soldering quality is good and we also found many SMD caps.

On the right side of the following large vertical PCB resides the combo PFC/PWM controller, most likely the CM6802S since its markings were fully erased, which in this case controls only the APFC circuit. On its left side the smaller IC is a UC2715D complementary switch FET driver, used by the ACRF topology. There is also a third IC on this side of the PCB, in the top right corner, which we couldn't recognize since it had no visible markings on it. In the middle of the PCB there are two opto-couplers which provide isolation between the two circuits and on the left side the supervisor IC is soldered, a PS232S. This IC provides OCP for up to four +12V rails, something not needed in this case since there is only one +12V rail and it doesn't integrate OTP, but provides an additional protection input pin so the OTP signal passes through this pin to the control IC.

Soldering quality on the main PCB is above average, that's for sure, but still isn't up to the levels that we are used to see from Enhance products. We spotted several hand made touch up jobs and some sloppy solder joints. Thankfully all component leads are short, meaning that the cutting guy did his job pretty well here. Finally we spotted five shunt resistors, three at the +12V area and two under the minor rails areas. The three shunts at +12V mean that this PSU initially had three +12V rails but Cooler Master preferred a single rail instead.

The cooling fan has Cooler Master's logo on it and its model number is DFS132512M (12V, 0.2A, 2.4W, 1500RPM, 34.44dBA, 78.13CFM). On the bottom side of the center badge we find its real manufacturer which of course is Young Lin Tech.

According to a spec sheet we found on Young Lin Tech's official site this fan is equipped with a plain sleeve bearing and not with a Hydro Dynamic one. On the contrary CM states that HDB is used, so we had to clear this up by cracking open the fan. In the end we discovered that the fan uses neither sleeve bearing nor HDB. The kind of bearing it uses is called Hysint bearing and is something in between. It provides longer lifespan and lower noise than sleeve bearing but it can't be compared with HDB/FDB. In the photos above notice the vertical V-shaped cutouts on the shaft of the fan. These curves pump the oil up and down on the bearing while the fan spins reducing friction. We contacted CM of course about this issue and they informed us that due to a patent on HDB/FDB each vendor has similar solutions with custom names, however there are also some differences in the design too.

Source : http://www.techpowerup.com/reviews/CoolerMaster/Silent_Pro_M2_1000W/