Overclock3D.Net :: Print Page :: PC Power & Cooling Silencer 750w CrossFire Edition ATX PSU

On April 19,1985, PC Power & Cooling began operations in a small warehouse just outside of San Diego, CA. Founded by Doug Dodson, a commodity trader and electronic hobbyist, the company's first products were custom fans to cool and quiet computers.

In 1986, the company introduced its Silencer 150 and Turbo-Cool 200, the industry's first ultra-quiet and high-performance power supplies. Other high-end products followed, the reviews were great, and the company continued to grow. In 1991, the company moved to a modern facility in Carlsbad, CA.

Over the last 22 years, PC Power & Cooling has produced many innovative products including: the first CPU cooler, the first PC heat alarm, the first independently-regulated PC power supply, the first redundant power system, the first NVIDIA-certified SLI supply, the first One Kilowatt computer power supply, and the first power supply with its own certified test report (Turbo-Cool 1KW).

The Silencer 750w Quad arrived in a plain white, double-walled corrugated cardboard box that does a very good job of protecting the unit from knocks and bumps during shipping - even on it's long journey from Carlsbad, USA.

We can see from the front of the box that the 750w Silencer boasts a peak output of 825w, 83% efficiency, Quad PCI-E connectors and a 3yr warranty.

The box is separated into 3 compartments for containing the power supply, cables and manual. It's good to see that PCP&C have situated the power supply in the middle of the box, further protecting the unit from any courier inflicted damage.

Removing the upper layer of cardboard reveals the S75CF in all its glory. We won't say much about its appearance just yet, but we can see that PCP&C have sealed it inside a clear plastic bag to prevent any minor scratching to the paintwork. Also included in the box are the following items:

• 1x PCP&C 750w Silencer unit.
• 1x Standard power cord.
• 4x ATX case screws.
• 1x Warranty leaflet.
• 1x Unit test report.

The included test report sheet contains all of results obtained from the testing of the power supply at the PCP&C factory. Just browsing over the page we can see some very impressive results from the rails under load and an efficiency rating of 84.56%.

Appearance

Known for their 'no nonsense' approach to manufacturing PSU's, PCP&C have very rarely ventured outside the safe confines of a plain black powder coated finish. However, on relasing the S75CF it's clear that they wanted to do something special for ATI fans. Finished in what PCP&C describe as a "Ferrari Red" powder coat finish, the S75CF looks simply gorgeous (but then I'm a big fan of Red) and the black fan grill and screws contrast extremely well. For those of us who have a PC colour scheme not suited to this unit, PCP&C do offer the Silencer 750w Quad in a matt black finish at a slightly cheaper price.

In keeping with all previous PCP&C units, the S75CF features a single 80mm fan at the back of the unit. PCP&C believe this design to be superior to the top-mounted 120mm fan design used by other manufacturers as it does not restrict the vertical space available to components such as heatsinks and capacitors.

As we can see from above, PCP&C have placed the specifications sticker at the top of the unit rather than at the side like most manufacturers. This has the advantage of not covering over the side of the power supply you are likely to see once it is installed in your case.

The front of the unit contains two rows of long thin grills that provide airflow to the components inside. Through these grills we can just about catch a glimpse of two large aluminium heatsinks and one of the transformers. A wire guard has also been used where the cables enter the unit, preventing the metal casing from cutting into the wires and avoiding chipping of the paintwork.

The internal layout of the S75CF is fairly spacious, with plenty of room between the 80mm fan and component board to help prevent any cooling dead spots. Attached to the banks of mosfets at the center of the unit are two large aluminium heatspreaders that almost touch the top of the casing, and are finned in a way that compliments the direction of airflow through the unit.

Sandwiched between the heatsinsks are two transformers and a capacitor. The larger of the two transformers (left) is most likely responsible for the single 60amp +12v rail, with the smaller transformer (upper-right) responsible for both the +3.3v and +5v rails. At the centre is a large black capacitor manufactured by Japanese company Nippon Chemi-con.

Since the widespread adoption of the 120mm fan design over the past few years, the 80mm design has taken a bit of a back seat. Many manufacturers believe that the 120mm design offers lower noise levels along with increased airflow. However, PCP&C have a different view on this matter:

Most low-noise ATX power supplies today utilize a top-mounted 120mm fan rather than a rear-mounted 80mm fan. The 120’s favorable reputation is based on the fact that under low to medium load conditions, the 120mm fan provides sufficient cooling at low RPM and low RPM fans are generally very quiet.

However, problems occur with this design when the load exceeds 50%-60%. Because the 120mm fan consumes about 1.5” of vertical space inside the PSU, heat sinks, capacitors, and other components are about 30% smaller in height compared to a PSU with a rear-mounted fan. The smaller parts can handle less current, so the maximum power available with the 120mm design is limited. And, because the heat sinks have less surface area, more air flow is needed with this design to keep the thermal situation under control. With 80%-100% load, the 120’s fan speed can double and the noise level can jump by up to 20dB.

With this in mind, let's take a look at the specifications of the ADDA manufactured 80mm fan used inside the S75CF:

• Model: AD0812UB-A71GL
• Size (mm): 80x80x25
• Bearing: BALL
• Speed (RPM): 3900
• Airflow (CFM): 50.0
• Noise (dBA): 41.0

Cables & Connectors

In previous reviews, PC Power & Cooling units have never been short of cables or connectors. After all, there's litte use in having a 750w power supply if you cant connect it to all of the devices in your system. We already know that the S75CF has quad PCI-E connectors, but let's take a closer look at what else is included..

If there's one thing I love about the way PCP&C package their PSU's, it has to be the use of a bog standard brown elastic band keeping all of the cables together. It just reinforces the fact that PCP&C would rather spend their time making the product rather than the packaging, and in a way almost feels like a 'fingers up' to manufacturers that go over the top on their packaging designs.

It's also good to see that PCP&C has professionally sleeved every cable right up to the first connector for better airflow and a tidier look. It would have been nice to see all cables fully sleeved up to the very end connector, but this would serve no purpose other than for cosmetic appeal.

The S75CF comes with a 24-Pin ATX connector and no way of reducing the connector down to 20-Pin. People wanting to use this unit on an older style 20-pin ATX motherboard will need to purchase a 24-Pin to 20-Pin connector separately. Quite a few of the most recently released motherboards still utilise the 4-Pin (P412v) connector, and for this reason PCP&C have included both P412v (4-pin) and EPS12v (8-pin) cables on the S75CF to ensure full compatibility.

With new graphics cards hitting the market that make use of the 8-Pin PCI-E connector it's good to see that PCP&C have provided two connectors that can be used in this format. For those of us who require 4x 6-Pin PCI-E connectors for configurations such a dual 8800GTX grapics cards, the 8-Pin connectors can be reduced to 6-Pin by simply snapping away the extra two blocks at the end of the connector.

With a maximum fluctuation of 0.11v, 0.08v and 0.02v on the +12v, +5v and +3.3v rails between 0% and 100% load conditions, it's fair to say that the PC Power & Cooling Silencer 750w Quad performed admirably. This once again goes to show that PCP&C are commited to manufacturing some of the best power supply's available.

PCP&C Silencer 750w Quad Efficiency Tests

PC Power & Cooling have never been a manufacturer that I'd associate with efficiency, however with the S75CF it looks like that is about to change. Managing 83.43% under 50% load and an even more impressive 84.08% efficiency under 100% load, the S75CF is actually one of the most efficient PSU's we've ever tested.

Temperature Testing

In our continuing efforts to make power supply reviews more thorough, rather than simply checking voltage stability, Overclock3D will now be recording the temerature of each PSU as it undergoes testing. Temperature recordings will be taken from the underside of the PSU's outer casing at 0%, 50% and 100% load levels using a laser infrared thermometer in an attempt to gauge how much heat is likely to radiate into the end-users case.

PCP&C Silencer 750w Quad Temperature Tests

Despite the use of a single 80mm fan, the S75CF never displayed signs of any potential cooling problems. At 100% load the temperature taken from the PSU casing was 35°c (13°c above ambient), showing that only a small amount of heat would be dumped into a PC enclosure.

Noise Level Recordings

Possibly the hardest part of any PSU review is summarising the level of noise given out by the unit. The threshold for what is considered 'noisy' varies from person to person and therefore what I may consider a quiet unit, another person may consider extremely loud. A common way to resolve this issue is to use a dBA meter to measure the units noise level, however this doesn't take into account the pitch (type) of noise emitted and whether it is likely to irritate end users.

For this reason OC3D records all power supplies at idle and load in wav format for you to make your own informed decisions. All recordings are taken at 30cm away from the PSU and outside of a PC case. You will need to remember that noise levels will be reduced by varying amounts once the PSU has been installed inside your PC enclosure.

0% Load Recording - Download
50% Load Recording - Download
100% Load Recording - Download

As you will be able to hear from the recordings above, the S75CF managed to remain extremely silent at both 0% and 50% load levels despite the use of an 80mm fan. In fact, I have no doubts that installing the S75CF inside an average PC would see the noise from the unit drowned out by normal case, motherboard and GPU fans.

Increasing the load to 100% saw the fan speed elevate significantly, causing a rise in the noise levels emitted from the unit. In all fairness it would be extremely difficult for the average PC enthusiast to put this much load on the PSU, but at this load level the S75CF wouldn't be suitable for 'Silent PC' enthusiasts or those building a HTPC.

	0%	50%	100%
+3.3v Rail	0w	33w	66w
+5.0v Rail	0w	50w	100w
+12v Rail	0w	360w	600w
Total	0w	443w	766w