Cooler Master is one of most recognisable and well-respected names in the PC component market. Over the years, Cooler Master has created some of the best power supplies, coolers and chassis around, not forgetting their gaming division CM Storm, which has delivered some very impressive headsets, keyboards, mice and much more too! With all that in mind, I am very excited to see another Cooler Master product in the office today, their brand new V750 power supply, which promises premium performance in a tidy and compact form factor.
“V Series power supplies feature the most stable and efficient power supply unit in its class thanks to exclusive 3D circuit design and Silencio FP technology. The V Series has fully modular flat cables with energy-saving 80PLUS Gold/Platinum ratings all delivered in a compact design smaller than most Power Supply Units (PSUs) in its class. The V series family is available in V550, V650, V750, V850, V1000 and V1200 watt variants perfect for gamers, enthusiasts and even system builders.” – Cooler Master
The V750 uses a unique 3D circuit design, Cooler Master’s own Silencio FP fan technology, fully modular flat cables, 100% Japanese capacitors and much more. The overall quality is reflected in the fact that this tidy, 150 x 140 x 86, form factor still delivers 750W of power at an 80 Plus Gold efficiency
There are three models available, the 550W, 650W and the 750W. We have the 750W at our disposal today, but all models come with 100-240Vac, good active PFC, >100,000 hours MTBF and are backed up by a reassuring 5-year warranty.
The box is very similar to previous Cooler Master designs and features a nice picture of the PSU, as well as a quick run down of the major features; 750W, Japanese Capacitors, 5-year warranty, Silencio fan and 80 Plus Gold.
Around the back, a run-down of the included cables and performance, but we’ll take a closer look at those ourselves in a moment.
In the box, you’ll find a nice cable storage bag, a collection of cable ties, four mounting screws and the mains adaptor.
A Closer Look – Exterior
The top of the v750 is really nicely designed, with a black trim that’s part of the main body of the PSU, but it’s finished with a brushed metal plate that surround the fan grille; a design that should blend in and even visually enhance most system builds.
Down the left side, we’ve got a painted on V750 and Cooler Master badge, which looks a lot more premium than the usual stickers we see on most units. There’s a little design flair to the top as well, a few simple lines, but it helps break up what would otherwise be a flat panel. The same design down the right side of the PSU, meaning it’ll look great from the side view regardless of the PSU’s orientation in your system.
Around the back, you’ll find the all-important AC line-in, a master power switch, which is always handy, as well as a lot of ventilation to allow heat to be exhausted from the unit; obviously an important factor to keep the unit as cool as possible.
Around the back of the V750, you will find a range of fully modular connectors, so cable management should be greatly improved within your system. We’ve got a split 24-pin motherboard connector, four PCI-e 8-pin connectors, more than enough for a multi-GPU configuration, as well as four peripheral connectors for all your SATA and Molex cables.
All of the cables for the V750 are really good quality, finish with all-black cables and all black connectors, which means they’ll blend in really easily within your system, keeping things looking neat and tidy. All of the cables are flat-type too, which will make cable routing easier and really help with passing cables through tighter spaces within your system.
A Closer Look – Interior
The interior of the V750 looks quite busy, but it’s also very neat and tidy, with a layout that leaves a nice amount of space between all major components. There’s very few cables trailing on the interior and what few there are, you’ll find them of little concern to the overall airflow within the unit. The 3D design helps space things out, which improves efficiency, reduces crosstalk noise and ripple, as well as reducing the overall size of the PSU.
A good AC line filtering stage, and like everything else in this PSU, it’s spaced nicely from other components and that should help reduce any interference between them.
There is a single main bulk capacitor which is rated for 560uF, 450V and up to 105c; as we said before, all the caps in the unit are high-quality Japanese hardware.
One the rest of the capacitors as well as mounting on to some of the 3D PCBs that are dotted around the PSU, you’ll notice a large finned heat sink, which combined with the fan should allow for impressive cooling of these components, without blocking airflow to the rest of the unit.
The LLC+DC-DC hardware, which will help improve the stability of the voltages, giving us clean power and low ripple.
A small header in the base for the fan connector.
The fan is one of Cooler Masters own, an A1202S Silencio FP fan. It offers up 52 CFM 2500 RPM, with a maximum noise rating of 29.7 dBa.
At eTeknix we take the power supply testing procedure very seriously and have invested a lot of resources into acquiring the appropriate testing equipment. For all power supply reviews we test the power supplies with dedicated power supply testing equipment. This means we are able to get the most accurate results from our testing as opposed to using software benchmarks (such as OCCT) or multi-meter readouts which are broadly inaccurate.
Our test machinery is as follows:
- Sunmoon SM-5500ATE Active Load Tester (1200W rated)
- Stingray DS1M12 USB Oscilloscope
- Voltcraft DT-10L laser tachometer
The eTeknix test procedure involves:
- Testing each power supply at 20/40/60/80/100% load (with balanced load across all rails) and measuring PFC (power factor correction), efficiency (actual power divided by power “pulled at the wall”) and voltage regulation (deviance from expected voltages of 3.3/5/12 on the main rails).
- Measuring ripple with an oscilloscope at 20/40/60/80/100% load.
- Measuring fan speed after a stabilisation period of five minutes at each load scenario using the Voltcraft DT-10L laser tachometer and a reflective strip on the fan.
- Testing each power supply’s OPP (Over Power Protection) mechanism and seeing how many watts each power supply can deliver before shutting down
Other things to consider are that
- We recognise that a single yellow 12 volt cable can provide only 6 Amps before overheating (which corrupts voltage regulation and efficiency) and so we used an adequate number of cables for each power supply to ensure there is not efficiency loss from poor cables selection
- Our Sunmoon SM-5500ATE power supply tester is not capable of testing more than 300W on each of the 12 volt rails so where a power supply provides more than 300W on a 12 volt rail that power is distributed over multiple 12 volt rails on the load tester. For example a power supply with one 12 volt rail supplying 750 watts would be spread equally over three 12 volt rails on the load tester, a power supply with two 450W 12v rails would be spread over four 12v rails on the load tester, two 225W 12v rails for each of the 12v rails on the unit.
- We use the same time scale and horizontal millivolt scale on our oscilloscope for all ripple tests, that is a 20ms T/DIV (horizontal) and a 0.02 V/DIV (vertical) meaning the scale is from -80mV to +80mV, ATX spec dictates that the 12v rail must fall within 150mv of ripple and the 3.3/5 within 50mv so that scale allows us to include both 150 and 50mV peaks. (Some older PSU reviews use different scales which were later ditched as the visual representation they give is inadequate, in these reviews written measurements are provided only).
- Deviance is the terminology used to represent the way voltages diverge from the expected values
Efficiency, PFC and Voltage Regulation
To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviance of each rail from its expected voltage.
Voltage regulation is pretty good overall, but there’s noticeably a slight drop at 100% load. I don’t expect this to be of any concern, but it couldn’t hurt for CM to improve on it in future models. On average there is only a very small deviance and that’s certainly a good thing.
Power efficiency is measured by calculating actual supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test 230v power supplies.
This may be an 80 Plus Gold rated unit, but it’s scored more into the Platinum rating that I would have expected. This is a great as the unit is going to be more energy-efficient and will save you some extra money on your electricity bill over time.
Power Factor Correction
Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. The aim of PFC is to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source – Wikipedia).
The PFC is about where I expected it to be and scores best from 40% load and above, which is most likely where your PSU will be getting the most use, so that’s another positive factor for this unit.
Noise and Ripple can easily be measured by an oscilloscope. These show how much voltage fluctuation there is on a particular rail. We tested the rail stability of the 3.3 volt, 5 volt and 12 volt rails using an identical time and millivolt scale for all graphs. millivolt ripple is measured by the peak to peak size of the voltage curve.
The latest ATX 12 volt version 2.3 specifications state that ripple from peak to peak must be no higher than 50 millivolts for the 3.3 volt and 5 volt rails, while the 12 volt rail is allowed up to 120 millivolts peak to peak to stay within specifications. Millivolt figures are stated to the closest increment of 5 given their variability.
|Load (%)||3.3V Ripple||5V Ripple||12V Ripple|
It’s safe to say that the ripple results are a little all over the place here, but I’m certainly not worried as they’re still well within the ATX regulations.
3.3 volt @ 100%
5 volt @ 100%
12 volt @ 100%
Over Power Protection and Max Wattage
Power supplies often quote as having various protection mechanisms such and the most important of these is Over Power Protection. In our testing we crank up the power draw until the power supply either shuts down (meaning the OPP mechanism is present and working) or blows up (meaning it is either not present or not working). We then note the maximum power consumption before the power supply shut down (or blew up).
This is bonkers, the unit went all the way up to 1229.4 before to OPP kicked in. This means you’ll be able to run well above the rated wattage without concerns of the system shutting down. Of course, I wouldn’t suggest you do this all day long, but for the occasional power spike while gaming or benchmarking, the extra headroom is always welcome; this is also a sign that CM have used high-quality components.
When testing in a power supply laboratory it is difficult to take fan noise readings as the noise from the Sunmoon test equipment and air conditioning corrupts everything. The next best thing in our circumstances was reading off the fan speed with a tachometer to get an idea for the noise. The ambient temperature during testing held constant at 22 degrees, with 1 degree of variation. Each power supply had a consistent time period of 5 minutes to stabilise between each load scenario.
In my experience, the following general relationships apply between noise levels and fan speeds, though it can vary greatly between the type of fan used.
- Below 800 RPM – Inaudible/Silent
- 800 to 1000 RPM – Barely audible
- 1000 – 1200 RPM – Audible but still quiet
- 1200 – 1400 RPM – Moderately noisy
- 1400 – 1800 RPM – Noisy
- 1800 RPM or higher – Intolerable
Pay close attention to those numbers on the left, as while it may look like the fan speed ramped up a lot at higher loads, it really only changed by 20RPM, which is as close to saying the fan speed was a constant 570-ish RPM, making is incredibly quiet and certainly inaudible for anyone that doesn’t have their ear pressed up against it.
The new V Series PSUs won’t be available till October, but we can tell you that the V550W, V650W and the V750W unit, which is the one we tested today, will be priced at £89.99, £99.99 and £109.99 respectively. I think this price is about 10% too high compared to the competition, but I expect retailers will address this with a slightly lower price, so I’ll reserve that judgement in my conclusion until they’re in stock at retailers.
The V Series is certainly a welcome addition to the Cooler Master range. Their build quality is certainly worthy of an award and the 3D Circuit design has made a huge impact on the cooling performance of the unit. The Cooler Master Silencio fan is certainly one of the of the better quality fans we’ve seen in a PSU and while it is rated for up to 2500RPM, it didn’t even get past 600RPM, meaning it was virtually silent. The internal layout benefits the free flow of air and passive cooling of the components, so the fan barely had to do any work and that means you get a cool and quiet PSU, which is pretty much what you would want anyway.
100% Japanese capacitors is a claim that’s often thrown around, but it’s clear that with the use of the best quality capacitors in this unit, there’s a clear performance improvement and we were able to run way past that 750W rating before the OPP kicked in, which is reassuring as your PC is less likely to simply shut down when the going gets tough.
Voltage regulation was very good overall, averaging out with a very small deviance across the load range. There was a slight droop at 100%, but it’s unlikely you’ll have any issues as it’s still within a safe margin, of course, it would still be even better to have a tighter voltage regulation at this load level, but it’s still good overall.
The ripple performance isn’t as good as some other units in this price range, or at this wattage, but given that there’s a maximum limit before a PSU is classed as “bad” in terms of how much ripple suppression, the V750 is still very well within that margin; some other units are very-very good, this one is just very good, hardly a bad thing really.
The flat and fully modular cables are a welcome bonus too, as they make cable routing and management very easy. There’s a good range of connectors too, so you should no issues getting everything hooked up in a mid-tower or full tower system. The compact size of the PSU also makes it compatible with a lot of mini-ITX chassis where space is critical.
- Good voltage regulation
- Flat cables
- Fully modular
- Virtually silent performance
- Exceptional OPP
- High-quality components
- Rock solid build quality
- Minor voltage droop at 100% load
- Higher ripple than some competitors, but still well within good tolerance
“The Cooler Master V750 offers great performance and efficiency for any mid-to-high end system. If you’re looking for a compact ATX PSU with virtually silent cooling and fully modular cables, this one should be at the top of your shopping list.”
Thank you Cooler Master for providing this review sample.