Cooler Master V750 Semi Modular PSU review

While we have focused in recent weeks on 1000W+ units, today we thought it was time to analyse an enthusiast 'mainstream' unit - the new Cooler Master V750 semi modular. This 750 watt power supply uses high grade Japanese capacitors and is 80 Plus Gold Certified. Available for around £95 in the UK, should this be making your shortlist? Cooler Master have had good success in the power supply sector in the last year and the V Semi Modular range targets a wide audience of enthusiast user. Cooler Master are promoting their use of high grade Japanese capacitors in the design, and the price hits just below the 'sweet spot' of £100 inc vat. This power supply will also target the high end gaming audience who are using two graphics cards in SLI or Crossfire configurations. Cooler Master V750 Semi Modular PSU overview: Powerful Single +12V rail for superior load balancing and VGA compatibility Modular cable designs for better cable management Japanese capacitor ensures an extended lifetime and excellent holdup times, in case of power fluctuation Custom DC-DC module design offers higher efficiency and voltage stability 80 PLUS Gold certified: up to 92% efficiency @ typical load. Cooler Master box artwork is quite attractive, and always in full colour. The rear of the box contains some technical information on the unit, useful if browsing in a store. The box packaging isn't the best. The power supply is just wrapped in a plastic bag and is protected inside an egg shell style cover. A user manual, regional specific power cable and mounting screws round out the accessories. The picture above left is the modular cabling supplied. Picture above right are the hardwired cables that exit the chassis. A little disappointing to see that the modular cables are all the flat 'ribbon' style, but the hardwired cables are all more traditional 'sleeved' - these are more difficult to route. Ideally I would have liked to see more modular cables, and less hardwired cables. Cable Connectors MB 20+4 pin x1 (570mm) CPU 4+4 pin x1 (630mm) PCI E 8 pin (6 pin +2) x4 (530 mm + 120 mm) SATA x8 (400mm + 150 mm) SATA x2 (530mm + 150mm) MOLEX x3 (400 mm + 150mm) MOLEX & FDD x3 / x1 (400 mm + 150mm) The supply is equipped with 4 x PCI e connectors to power two graphics cards. The relatively modest length of the ATX and EPS cables might prove problematic with the largest tower cases on the market in 2014. The Cooler Master V750 Semi Modular is an attractive, compact design with ridges on the side panels above the company logo and product name. The quality of finish is good, if not exceptional. The unit didn't pass our ‘screwdriver’ test. This involves running the head of a Philips head driver down the side of the chassis with light to medium force. After all, how many times have you accidentally connected with a power supply during a system build? A little scratch was left on the paintwork. The top of the unit is two tone, with the company badge in the center. The large fan is visible, and we will look at this closely when we crack the unit open. One side of the power supply is vented to aid with air flow. At the side is a power connector and plug. The other side of the power supply is home to the hardwired cables and modular panel - which is foolproof. I was very disappointed to see the quality of the sleeving on the hardwired cables. The image above shows that the outer sleeving has came lose from the chassis, leaving some of the cables exposed. Photography is always the first stage of our reviews, so it wasn't due to it being badly manhandled during testing either. Cooler Master V750 Semi Modular Power Supply DC Output +3.3V +5V +12V -12V +5Vsb Max Output 25A 22A 62A 0.3A 2.5A Total Power 120W 744W 3.6W 12.5W 750W The Cooler Master V750 Semi Modular power supply can deliver 62 AMPS on the +12V rail, for a total of 744 watts of power. Cooler Master are using a Yate Loon fan, model number D12BH-12, which is rated at a maximum of 3,000 rpm, 101 CFM and 47dBa. Highly unlikely it will ever spin that high in this unit however. The OEM for this particular supply is Enhance Electronics. They have earned a good enough reputation over the years, although they fall short of market leaders Seasonic, Delta or Flextronics. This is a full bridge implementation featuring a LLC resonant converter on the primary. The secondary side uses mosfets to regulate the +12V rail. The filtering starts with a pair of Y caps and X caps. It continues to the main PCB and contains two Y caps, two X caps, two CM chokes and an MOV. Two DC-DC converters produce minor rails, as seen in many of the latest designs we have reviewed in 2014. The primary capacitor is high grade Japanese PANASONIC, rated 105C 560uF, 450V. Other capacitors on the board are high grade 105c - Nippon Chemi Con, Suncon and Rubycon branded. Another close up look at the poor quality sleeving on the hard wired cables which we mentioned earlier in the review. S0me of the wires are exposed on the outside as they enter the chassis. On this page we present some high resolution images of the product taken in our professional studio. These will take much longer to open due to the dimensions, especially on slower connections. If you use these pictures on another site or publication, please credit Kitguru.net as the owner/source. Additional technical assistance: Peter McFarland and Jeremy Price. Correctly testing power supplies is a complex procedure and KitGuru have configured a test bench which can deliver up to a 2,000 watt DC load. Due to public requests we have changed our temperature settings recently – previously we rated with ambient temperatures at 25C, we have increased ambient temperatures by 10c (to 35c) in our environment to greater reflect warmer internal chassis conditions. We use combinations of the following hardware: • SunMoon SM-268 • CSI3710A Programmable DC load (+3.3V and +5V outputs) • CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4) • Extech Power Analyzer • Extech MultiMaster MM570 digital multimeter • Extech digital sound level meter • Digital oscilloscope (20M S/s with 12 Bit ADC) • Variable Autotransformer, 1.4 KVA We are combining +12V output to get the results. DC Output Load Regulation Combined DC Load +3.3V +5V +12V +5VSB -12V A V A V A V A V A V 75W 1.23 3.33 1.19 5.05 4.95 12.21 0.50 5.01 0.20 -12.04 150W 2.17 3.30 2.83 5.03 10.08 12.17 1.00 4.99 0.30 -12.04 375W 6.16 3.29 6.05 5.01 26.16 12.12 1.50 4.99 0.50 -12.08 565W 10.32 3.27 10.86 4.97 38.33 12.03 2.00 4.97 0.60 -12.09 750W 10.72 3.25 13.82 4.94 53.60 11.92 3.00 4.95 0.80 -12.09 Load regulation is reasonably good, although it fails short of the best we have seen this year. Cooler Master V750 Semi Modular PSU Maximum Load 794W We managed to reach around 794W before the unit would shut down gracefully, after the protection kicked in. Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly. Cross Load Testing +3.3V +5V +12V -12V +5VSB A V A V A V A V A V 734W 1.0 3.32 1.0 5.05 60.0 11.88 0.2 -12.05 0.50 4.97 154W 15.0 3.25 15.0 4.93 2.0 12.20 0.2 -12.07 0.50 4.95 A decent set of results, although again, we noticed some movement on the +12V rail when hit with 60 AMPS. We then used an oscilloscope to measure AC ripple and noise present on the DC outputs. We set the oscilloscope time base to check for AC ripple at both high and low ends of the spectrum. ATX12V V2.2 specification for DC output ripple and noise is defined in the ATX 12V power supply design guide. ATX12V Ver 2.2 Noise/Ripple Tolerance Output Ripple (mV p-p) +3.3V 50 +5V 50 +12V1 120 +12V2 120 -12V 120 +5VSB 50 Obviously when measuring AC noise and ripple on the DC outputs the cleaner (less recorded) means we have a better end result. We measured this AC signal amplitude to see how closely the unit complied with the ATX standard. AC Ripple (mV p-p) DC Load +3.3V +5V +12V 5VSB 75W 10 5 5 10 150W 10 5 10 15 375W 10 10 20 20 565W 15 10 25 25 750W 15 15 30 30 Ripple suppression is very good on all rails, part of the credit has to go to the use of high grade Japanese capacitors throughout the design. The +12V rail peaks at 30mV for instance. Both +3.3V and +5V rails peak at 15mV, which is excellent. Efficiency (%) 75W 88.12 150W 90.20 375W 92.12 565W 91.44 750W 90.03 Efficiency peaks at just over 92 percent at 50 percent load, dropping to just over 90 percent at full load. Strong results. We take the issue of noise very seriously at KitGuru and this is why we have built a special home brew system as a reference point when we test noise levels of various components. Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on components we are testing. It also brings us slightly closer to industry standards, such as DIN 45635. Today to test the power supply we have taken it into our acoustics room environment and have set our Digital Sound Level Noise Decibel Meter Style 2 one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself. As this can be a little confusing for people, here are various dBa ratings in with real world situations to help describe the various levels. KitGuru noise guide 10dBA - Normal Breathing/Rustling Leaves 20-25dBA – Whisper 30dBA - High Quality Computer fan 40dBA - A Bubbling Brook, or a Refrigerator 50dBA - Normal Conversation 60dBA - Laughter 70dBA - Vacuum Cleaner or Hairdryer 80dBA - City Traffic or a Garbage Disposal 90dBA - Motorcycle or Lawnmower 100dBA - MP3 Player at maximum output 110dBA - Orchestra 120dBA - Front row rock concert/Jet Engine 130dBA - Threshold of Pain 140dBA - Military Jet takeoff/Gunshot (close range) 160dBA - Instant Perforation of eardrum Noise (dBA) 75W <28 150W 29.3 375W 31.5 565W 33.5 750W 35.4 The fan doesn't spin much at lower loads, meaning the power supply is very quiet. At around 300 watts, the fan kicks in a little, becoming audible although never that intrusive. At full load, the fan spins much higher, and noise levels hit 35.4dBa. Temperature (c) Intake Exhaust 75W 36 40 150W 38 42 375W 39 48 565W 45 59 750W 47 60 The fan maintains good temperatures inside the chassis, and it spins up considerably in the upper part of overall load demand. Maximum load Efficiency 794W 89.7 For those interested, we measured efficiency when stressing the unit to breaking point. 89.7 percent efficiency at 823W … hardly practical, but interesting regardless. Cooler Master have been releasing some high grade quality power supplies in 2014 and have earned a solid reputation among the enthusiast user base. They work with a variety of OEM partners, bringing a wide range of supplies to market in various price zones. Strangely, the V750 Semi Modular is not a Seasonic OEM partner product, like the Vseries 1000W which we reviewed last May. Enhance is the OEM partner for this particular unit and to be fair .. its a solid, reliable implementation. It doesn't quite scale to the same heights as a Seasonic, Delta or Flextronics design, but it is very capable. The V750 Semi Modular is an important power supply for Cooler Master, because it is powerful enough to handle a reasonably high end dual GPU SLI or Crossfire system build, and hits the pricing 'sweet spot' under £100. The compact physical dimensions will suit a vast array of potential system builds, especially in the high end 'media center' category - those people who want a small HD media system to sit beside a TV, but cram it with enough high end hardware to be able to power any modern Direct X 11 game at 1080p. The biggest let down with this unit is the cabling. The mixture of flat ribbon style modular cables and traditional sleeved hardwired cables looks ugly and Cooler Master really should have reduced the number of hard wired cables. The quality of the sleeving on our review sample was also poor, with part of the sleeving stopping short of entering the chassis. This could very well be just an issue with our particular review sample, but we can only discuss what we have in hand. Technically, the V750 Semi Modular performs well. Load regulation could have been a little better, but ripple suppression and efficiency both rate as excellent. Right now you can buy the Cooler Master V750 Semi Modular power supply in the United Kingdom from Amazon, for around £92 inc vat. It certainly has no shortage of competition and just misses out on our MUST HAVE Award. Discuss on our Facebook page, over HERE. Pros: Ideal for a dual GPU SLI or Crossfire system. ripple suppression is excellent. excellent efficiency. High grade Japanese capacitors throughout. quite quiet. Cons: Sleeving is poor. mixture of cable styles looks ugly. too many hard wired cables. stiff competition at the price. cable length not long enough for the biggest tower cases. Kitguru says: A very capable power supply that deserves serious consideration. There is however no shortage of competition in the £90-£100 sector.