Efficiency, Differential Temperature and Noise
Efficiency
Efficiency is defined by the power output divided by the power input and is usually expressed as a percentage. If a PSU were a 100% efficient (which none are) 850 watts of AC power going in would result in 850 watts of DC power coming out (with no waste heat to dissipate). In the real world there are always inefficiencies and power is lost in the form of heat during the conversion process. Newer revisions to the ATX12V Power Supply Design Guide V 2.2 have continued to increase the efficiency recommendations for PC switching mode power supplies and now lists both required and recommended minimum efficiencies.
We measured the AC power input to the PRIME Ultra 850W Titanium PSU with an Extech power analyzer while the total DC load was found by adding all the individual +3.3V, +5V, +12V, -12V and +5VSB loads together.
The overall efficiency of the PRIME Ultra 850W Titanium power supply is excellent and easily meets the criteria for 80 Plus Titanium certification, even while operating on 120 VAC and at elevated temperatures.
80 Plus Program
Note: Tests conducted at room temperature (25°C)
In addition to the familiar 80 Plus efficiency testing, Seasonic is now using two other certifications for the PRIME Ultra 650W, 750W, and 850W PSUs for efficiency and noise.
Cybernetics ETA Efficiency Level A: The top-level Cybernetics rating badge testifies that the PRIME Ultra 850W Titanium PSU operates between 91% and 94% efficiency at all times, at any load. The power supply achieves above 77% efficiency on the +5VSB rail and merely consumes less than 0.15W when the system is idling.
Cybernetics LAMBDA Noise Level A++: The noise output of the power supply is as good as it can be; the PRIME Ultra 850W Titanium PSU earned the LAMBDA Noise Level A++ rating as its noise output stays below 20 dB(A) during operation.
Differential Temperature and Noise Levels
To simulate a demanding environment, some of the warm exhaust air from the PSU under test is recirculated back to the intake through a passive air duct, which allows the PSU air inlet temperature to increase with load, just like it would in a real PC.
The differential temperature across the power supply was calculated by subtracting the internal case air temperature (T in) from the temperature of the warm exhaust air flowing out the back of the power supply (T out).
Thermocouples were placed at the air inlet and exhaust outlet. The ambient room air temperature was 23ºC (74ºF) +/- 0.5ºC during testing.
T out = temperature of air exhausting from power supply
T in = temperature of air entering power supply
Delta T = T out – T in
Sound pressure level readings were taken 3’ away from the rear of the case in an otherwise quiet room. The ambient noise level was ~27 dBA. The power supply was tested with the Hybrid Fan Control turned On (enabling fanless operation at low to mid power levels).
*Fan not spinning
The PRIME Ultra 850W Titanium PSU cooling fan did not start spinning until we entered the 75% load test. At the 75% load mark the fan noise was relatively quiet and even at the 100% the fan noise never really became loud. Having great efficiency helps keep the waste heat and fan noise to a minimum.
(Courtesy of Seasonic)
Nice Review. I always enjoy
Nice Review. I always enjoy the details. : )
One question though. Are there any companies that are selling PSU’s in the 700-900 Watt range, that have a better efficiency than Titanium ?
Dell was supposedly the first to get Titanium on the market, but I was wondering if there’s a company that has been bold, and put a product that is beyond Titanium+ ?
Personally, I want the most efficient PSU possible, because of high room temps, due to climate of my country.
Thank you – we are glad you
Thank you – we are glad you enjoy the reviews! Currently, within the 80 Plus Orginaization certification criteria, Titanium is the highest rating. Keep in mind that this is a minimum specification and a vendor can always produce a product that exceeds the criteria (even better efficiency). For example, if Seasonic came out with a new Super Ultra PSU that achieved 98% efficiency it would still be labelled a Titanium unit.
Thanks for the response Lee.
Thanks for the response Lee. : )
Do you know of any PSU’s that meet the criteria that you mentioned ?
I thought you would be best to ask, because your company probably sees tons of titanium PSU’s, and maybe you remember the literally best % efficiency PSU.
I would be very interested in buying a PSU that exceeds Titanium Standards.
If you can’t remember any, that’s alright, Titanium is great for now, but I’m always looking for better.
I have high temperatures where my PC sits, so every % point of efficiency, makes a big difference to me.
No, I am not aware of any ATX
No, I am not aware of any ATX PSUs that operate up to 98% efficiency – sorry. Most of the "Titanium" series PSUs I have tested in the last year peak at about 94% efficiency.
If you really want to optomize the efficiency of your PC, make sure you match the PSU to the actual load your PC is pulling. For example in this review, the efficiency of the PRIME Ultra 850W Titanium peaks at about 60% load. Ideally you should measure the actual load of your PC with an inexpensive AC watt meter and then select a PSU that has a peak efficiency around that load. An 850W PSU would be ideal for a PC that draws 450~550W. Hope this helps.
Cooler Masters Made in Japan
Cooler Masters Made in Japan 1200W unit exceeds Titanium standards.
That being said, why do you need such high efficiency? 80 Plus ratings are a scam and youre better off with a bronze unit thats high quality than some arbitrarily 80 plus titanium rated thing.
Ya why would anyone want to
Ya why would anyone want to know what efficiency to expect with a shiny marketing sticker. I mean like c’mon the bronze is good enough for gaming right but it is just arbitrary anyways. Who cares I can get a 300W supply for like 15 bucks 80 plus standards are such a sham.
How long is a power supply
How long is a power supply run at say, 450w to test the temperature of air coming out and noise?
We test a PSU for 30 minutes
We test a PSU for 30 minutes at each load point to let temperatures equilibrate.
I bought a Prime Titanium 650
I bought a Prime Titanium 650 about 8 months ago. What makes this new model any different?
For example, it says: “The PRIME Ultra Series builds upon the PRIME Titanium platform by delivering extremely tight voltage regulation on the three primary rails (+3.3V, +5V and +12V) and providing superior AC ripple and noise suppression with an extended hold-up time.”
Does that mean the Ultra has better voltage regulation, AC ripple and noise suppression? They’re both Titanium rated, so should have the same basic specs.
Then we get this “informative” blurb: “This leading member of the series boasts an improved DC to DC converter design where pins and a copper plate replace cables to connect the back panel and the PCB for increased efficiency.”
Does that mean the original Prime DOESN’T have pins and a copper plate?
The packaging looks exactly the same as the one I got, and there is no Ultra marking on the box.
Help me out here…
From their website: ‘Each
From their website: ‘Each PRIME Ultra Series power supply will also ship with a SATA 3.3 adapter to support the “Power Disable” (PWDIS) feature of the newer, high-capacity hard drives. The inline capacitors on the cables were removed, which takes away the bulkiness inside the system. To maximize flexibility, the 180-degree SATA connectors ensuring more flexibility and easier installation.’
The new “Ultra” series
The new "Ultra" series incorporates minor tweaks to the basic PRIME Titanium platform. The features the reader above pointed out are the most obvious external differences. Internally the new Ultra series appears virtually identical – Seasonic doesn't say what minor tweaks they may have made to the circuit design, but I'm guessing they are minor as the PRIME Titanium was already a VERY GOOD platform. I believe the earlier PRIME Titanium units (without the Ultra name) also had the pins & plate. Seasonic is just pointing this out as an included feature. If you have a PRIME Titanium PSU you don't need to worry about missing out on any big improvements. As far as basic performance parameters, I have seen no real difference between the original PRIME Titanium and the new Ultra models: same great efficiency, voltage regulation, AC ripple suppression, etc.!