Seasonic G Series 550W Power Supply review

Last week we reviewed the latest Seasonic G Series 360W Power supply and today we focus on the upper/mid range power output unit in the range, the G Series 550W Power Supply. Seasonic are offering the new G Series power supplies in 360W, 450W, 550W and 650W capacities targeting the cost conscious enthusiast audience who are in the market for a quality power supply without wanting to pay a fortune. The Seasonic G Series 360W is undoubtedly an excellent supply, hitting a price sweet spot of £46.99 inc vat in the UK right now. I still believe Seasonic will have a problem selling a lot of them, due mainly to public perception of wattage ratings and what they feel would be needed to run a system today. To stress the point of ‘overestimating power demand’ we can link you to a review we published a short while ago which focused around the Asus Maximus V Formula Z77 motherboard. On the power consumption page, the system demanded only 191 watts under 100% Cinebench R11.5 load. That system comprised a Core i7 3770k, overvolted and running at 4.8ghz, with 16GB of Corsair Dominator memory, running at 2,666mhz. There were also several drives in the mix, and a Corsair H100 liquid cooling the overclocked processor. The G Series has been designed by Seasonic to target a much broader audience who aren't willing to spend a lot of money on a quality supply. That doesn't mean Seasonic are willing to compromise on quality however, because the 550W unit which we are reviewing today is 80 Plus Gold Certified with high grade Japanese components inside. Not only that, but the 550W unit is a modular design. The asking price? A very modest £76.99 inc vat in the United Kingdom today. Features: 80 Plug Gold Certified DC to DC Converter Design Tight Voltage Regulations (±3%) Smart and Silent Fan Control High Reliable Aluminum Electrolytic Capacitors Conductive Polymer Aluminum Solid Capacitors Detachable Modular Cables High Current Gold Plated Terminals 12cm Ball Bearing Cooling Fan Ultra Ventilation (honeycomb structure) Mulit GPU Technology Support Universal AC Input 5 Year Warranty The Seasonic G Series 550W Power Supply ships in a very dramatically designed box, like the 360W version of the supply. No image of the unit on the front of the box, just an 80 Plus Gold logo bottom right. Seasonic bundle a case sticker, mounting screws, user manual, regional specific power cable and cable ties. They include a cable bag to store the modular cables. Always handy to have. The G Series 550W isn't a pure modular design and a single thick cable emerges from the front of the chassis. This features the main M/B cable and an EPS12V/ATX12V cable. The cables are all 'flat' ribbon style, to help improve air flow. The G-550 has the same cable configuration as the G-450, including two 6/8 pin PCIE connectors - suitable for a single high end graphics card. The Seasonic G Series 550W Power Supply is finished to the same standard as the 360W unit in the same family. It is plain but will look fine in a variety of systems with side panel windows. The same high quality paintwork is present, although it does attract fingerprints quite easily. A large 120mm fan takes centerstage at the top of the chassis, hidden behind a black protective grill. The rear of the chassis features a honeycomb vent panel next to a power connector and switch. The modular cables all connect into a single panel on the opposite end of the chassis. These are not labelled, although the cables can only fit into specific ports, being 3+3 pin and 4+4 connectors. The range of G-Series units, shown above. the G-550 unit can deliver up to 45A on the +12v output. Seasonic are using an ADDA AD1212MB-A70GL fan. This is a ball bearing unit rated at 0.33A/12V. This is identical to the fan used in the G360 unit. The unit follows a clean layout with several rows of heatsinks separating the components. The G550 is using a high grade Nippon Chemi Con capacitor, rated 390 µF x 420 V @ 105c. Seasonic are using high grade Japanese capacitors in the secondary stage from Chemi Con and Rubycon, all rated to 105c. The cables are fully sleeved into the chassis and tied into position. This should help resolve any concerns with long term fraying. On this page we present some super high resolution images of the product taken with the 24.5MP Nikon D3X camera and 24-70mm ED lens. 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 • SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) • Digital oscilloscope (20M S/s with 12 Bit ADC) • Variable Autotransformer, 1.4 KVA We combine all +12V output for the results below. DC Output Load Regulation Combined DC Load +3.3V +5V +12V +5VSB A V A V A V A V 110W 1.18 3.36 1.18 5.06 8.02 12.11 0.50 5.06 220W 2.07 3.35 2.07 5.05 16.13 12.08 0.50 5.03 340W 3.04 3.35 3.05 5.03 25.12 12.06 1.00 5.02 445W 4.12 3.33 4.06 5.01 33.23 12.05 1.50 5.01 550W 5.13 3.31 5.03 4.99 41.03 12.03 2.50 5.00 Seasonic G Series 550W Power Supply Maximum Load 651W Load regulation is strong across the output range. The power supply delivered 651watts of power before it would shut down, safely. This is an excellent result and follows the Seasonic strategy of over-specifying the unit for the wattage rating. 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 493W 1.0 3.36 1.0 5.06 40.5 11.98 0.2 -12.05 0.50 5.02 153W 15.0 3.29 15.0 4.99 2.0 12.09 0.2 -12.11 0.50 5.03 The power supply is well designed and it coped well with our demanding Cross Load tests. When hit with 40A on the +12V rail it held close to a reference result at 11.98V. Other rails delivered good results. 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 110W 10 10 20 10 220W 10 15 25 10 340W 15 15 30 15 445W 20 20 45 20 550W 25 25 55 20 Noise suppression is good, peaking at 55 mV at full load on the +12V output. All other rails held to 20mV-25mV when loaded. Efficiency (%) 110W 87.11 220W 89.77 340W 91.45 445W 90.76 550W 88.88 Efficiency is excellent, peaking over 91 percent at around 50 percent load. At full load this drops to just below 89 percent efficiency. 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 SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself. That said, measuring lower than 28dBa proves very difficult, unless in strict laboratory conditions. 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) 110W 28.0 220W 29.5 340W 31.7 445W 32.7 550W 33.2 The fan maintains a low level of noise, even when tasked with 450W power. This rises in the last 15% of power output, but the results are still impressive. Temperature (c) Intake Exhaust 110W 36 38 220W 38 42 340W 41 47 445W 44 52 550W 46 56 The efficiency of the unit allows the large fan to spin very slowly at all times. Temperatures rise to a 10c above ambient intake at full load. Maximum load Efficiency 651W 87.1 Pushing the PSU above its rated limits generates an efficiency level of around 87.1%. This is not a viable ‘real world’ situation, but its interesting nonetheless. The Seasonic G Series 550W power supply fits well against the 360W unit in the same family. These budget oriented power supplies have not compromised in quality and the technical capabilities of the range we have looked at so far are certainly impressive. Aesthetically the design is very simple. The plain black paint with simple stickers detailing specifications and branding is not intrusive. The paint is deep and can resist rough handling without leaving a mark, although it does tend to attract fingerprints quite easily. The understated design will suit a variety of systems, including those with Cathode lighting and side window panels. Technically, the design is very capable and designed well to withstand heavy load variance. It also managed to deliver 650W before shutting down. Noise suppression falls well within rated tolerance levels although the G Series is slightly weaker in this regard compared to their other, more expensive series. That said, this won't really make a difference to the end user as the results are still excellent. We mentioned in the previous review that the 360 wattage rating of the entry level G-Series power supply will unfortunately be enough to put off a large portion of the enthusiast audience. The G550 is starting from a higher base point which should guarantee good sales for Seasonic. Additionally, the 550W model is only around £30 more expensive which is quite an achievement for a high grade 550W rated unit which is both semi modular and 80 Plus Gold Certified. This modular design makes it more appealing for media center fanatics on a budget. We feel this is a very welcome addition into the new Seasonic range, and the asking price makes a potential purchase all the more palatable. You can buy from Overclockers in the United Kingdom for £76.99 inc vat. Pros: clean design. technically very capable. quiet. can deliver 650W under load. Cons: A lot of competition at this price point. Kitguru says: Another winner for Seasonic, and the price is right.