Seasonic M12D 750w ATX PSU

Simulated Load Testing

Simulated Load Testing

To provide our readers with the most accurate results, Overclock3D uses a professional grade SunMoon SM-268+ ATE load tester capable of placing a sustained load of 1690w across a total of six rails (including +5vsb and -12v) on the PSU. Unlike our previous resistor-based load tester, the SM-268+ gives us the ability to adjust amperage loads in increments as small as 0.01A while also measuring voltages and wattage readings on-screen.

During today's tests, we will be placing the M12D under 25%, 50%, 75% and 100% load levels at both room temperature and inside a hot box regulated to a temperature of around 50°C. Additional cross load tests will also be performed under these conditions to simulate how the PSU would perform with a heavily uneven distribution of load.

Seasonic M12D 750w SM-268+ Results @ Room Temp
  +3.3v +5.0v +12v1 +12v2 +5vSB -12v AC Watts /
 DC Watts
 Efficiency Intake /
 Exhaust
Δ Temp
Test 1
(Low)
 5.50A 3.75A6.25A6.25A 0.75A 0.20A 226w /
 199w
 88.05% 22.6°C /
 25.2°C
 2.6°C
 3.35v4.96v12.45v12.43v 4.99v -12.40v
Test 2
(Med)
 11.00A 7.50A 12.20A12.20A 1.5A 0.40A 431w /
 388w
 90.00% 23.1°C /
 29.4°C
 6.3°C
3.30v4.91v12.37v12.35v 4.94v -12.41v
Test 3
(High)
16.50A 11.25A 18.75A18.75A 2.25A 0.60A 662w /
 588w
 88.82% 23.9°C /
 31.5°C
 7.6°C
3.24v4.86v12.27v12.26v4.89v -12.47v
Test 4
(Full)
 22.00A 15.00A 25.00A25.00A 3.00A 0.80A 885w /
 782w
 88.36% 24.5°C /
 32.8°C
 8.3°C
3.19v4.80v12.18v12.20 v 4.84v -12.55v
Test 5
(x-load)
23.00A20.00A0.50A0.50A0.75A0.20A 233w /
191w
81.97%20.2°C /
26.5°C
 6.3°C
3.27v4.87v12.45v12.44v4.96v-12.45v
Test 6
(x-load)
 3.00A 5.00A 31.00A31.00A 0.75A 0.20A 906w /
801w
88.41% 23.5°C /
 31.6°C
 8.1°C
3.25v4.87 v12.18v12.19v4.92v -12.84v

*slobbers*...do you see what I see? Yes the 90% efficiency at a DC load of 388w is not a typo and come in at just the kind of load level the average enthusiasts PC system is likely to run at when under a light stress. The rest of the results also back up the M12D's 80-PLUS Silver certification with an average of 88% efficiency being recorded throughout all of the non-crossload testing.

Unfortunately it's not all good news though as the M12D puts out some slightly shady voltages in Test 1 with the +12v rails bordering on 12.45v. Test 2 and 3 manage to bring these voltages down a tad with the additional load being placed on the PSU, but throughout the testing I couldn't help but notice all the voltage outputs bouncing around like a 5yr old who's just downed a can of Red Bull. Seriously, it was quite hard to take a reading without it flicking over to another number +/-0.03v either side of what I'd begun writing down.

Seasonic M12D 750w SM-268+ Results @ 50°C
  +3.3v +5.0v +12v1 +12v2 +5vSB -12v AC Watts /
 DC Watts
 Efficiency Intake /
 Exhaust
Δ Temp
Test 1
(Low)
 5.50A 3.75A6.25A6.25A 0.75A 0.20A 226w /
 199w
 88.05%50.5°C /
54.5°C
 4.0°C
 3.35v4.96v12.45v12.43v 4.99v -12.40v
Test 2
(Med)
 11.00A 7.50A 12.20A12.20A 1.5A 0.40A 431w /
 388w
 90.00%52.0°C /
54.2°C
 2.2°C
3.29v4.91v12.36v12.33v 4.94v -12.41v
Test 3
(High)
16.50A 11.25A 18.75A18.75A 2.25A 0.60A 660w /
 588w
 89.09%50.9°C /
56.5°C
 5.6°C
3.24v4.85v12.27v12.26v4.88v -12.48v
Test 4
(Full)
 22.00A 15.00A 25.00A25.00A 3.00A 0.80A 885w /
 782w
 88.36%51.8°C /
59.7°C
 7.9°C
3.19v4.79v12.18v12.29 v 4.82v -12.56v
Test 5
(x-load)
23.00A20.00A0.50A0.50A0.75A0.20A 233w /
190w
80.85%50.6°C /
55.5°C
 4.9°C
3.26v4.87v12.45v12.44v4.96v-12.45v
Test 6
(x-load)
 3.00A 5.00A 31.00A31.00A 0.75A 0.20A 906w /
801w
88.41% 50.0°C /
58.6°C
 8.6°C
3.25v4.87 v12.17v12.16v4.92v -12.84v

Things didn't get any better for the voltage stability in the 50°C testing either (why would they?) with most of the voltage readings being around -0.01v lower than the room temperature tests, and still fluctuating. One thing that did have me grimacing slightly was the -12v rail in Test 6 which hit -12.84v. Sure it's nowhere near as likely to do damage as the +12v rails, but some better regulation wouldn't have gone amiss.

Efficiency managed to stay almost exactly the same with that magical 90% still being achieved in Test 2 despite the PSU components being under a lot more stress due to the increased temperature.

Seasonic M12D 750w Scope Results @ 50c
  +3.3v +5.0v +12v1 +12v2
Test 1
(Low)
T1_3.3VT1_5VT1_12Vt1_12v2
Test 2
(Med)
t2_3.3vt2_5vt2_12vT2_12V2
Test 3
(High)
t3_3.3vt3_5vt3_12vt3_12v2
Test 4
(Full)
t4_3vt4_5vt4_12vt4_12v2
Test 5
(x-load)
t5_3.3vt5_5vt5_12vt5_12v2
Test 6
(x-load)
t6_3.3vt6_5vt6_12vt6_12v2

Both the +3.3v and +5.0v rails managed to put out some nice clean lines on the scope, with ripple staying below 8mV in most cases and only hitting as high as 11mV in test 4 and 5. The +12v1 and +12v2 rails on the other hand were giving me crazy eyes with the scope set to 2ms, producing some weird patters that I've never come across before.

Slowing things down to 5ms readings gave a clearer picture of what was going on with ripple staying below 43mV throughout the testing. Not bad at all, even though I have had better elsewhere darling.
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Most Recent Comments

21-03-2009, 07:26:22

JN
"Seasonic are well known for their silent yet powerful PSU's, but does their latest modular model follow suit? We find out."

http://www.overclock3d.net/gfx/artic...072344991s.jpg

Seasonic M12D 750w ATX PSU

21-03-2009, 07:58:31

w3bbo
Nice review m8. Bit on the pricey side for a 750w though imo.

21-03-2009, 08:14:26

JN
Quote:
Originally Posted by name='w3bbo'
Nice review m8. Bit on the pricey side for a 750w though imo.
Agreed. Though with 90% efficiency you might get your money back in...oooh...50 years

21-03-2009, 09:13:34

Rastalovich
Got 2x 600w M12 over a year ago for around 100 each bundled with some icybox external caddies (that I sold on for about 20).

They're good enough units. Neither of them liked doing a 8 pin pcie adapter for a gtx280 tho, wouldn't even start it. Had to use a 500w pc&p.

I'm happy to see they've changed the modular banks to reflect 2x 8 pins in this model, as the majority of us would realize, it should be 'capable' of 4x 8 pin pcie (even with 2x adapters) - it would have been interesting if it would work considering my previous experience.

I'd like to see more variety in the ability to customize modular connections as a result.

Classic review once again, 150 is quite steep tbh.

21-03-2009, 09:15:01

w3bbo
Dare I say it...needs more Jiggawatts....to be competitive.

Although having said that 1kw is OTT for most systems.

21-03-2009, 10:55:58

JN
Quote:
Originally Posted by name='w3bbo'
Dare I say it...needs more Jiggawatts....to be competitive.

Although having said that 1kw is OTT for most systems.
Yeah I think Seasonic's take on this PSU was "You dont need 1KW, so lets spend the money on good components and performance elsewhere".

21-03-2009, 15:08:25

Freak
But then if a psu isnt being pushed then wont it be more efficient than one running flat out? Plus lasting longer.

21-03-2009, 15:33:20

JN
Quote:
Originally Posted by name='Freak'
But then if a psu isnt being pushed then wont it be more efficient than one running flat out? Plus lasting longer.
Not always mate. Different PSU's have different efficiency curves. Most of the time efficiency peaks at around 50-75% load, but I've seen some PSU's hit their highest efficiency at close to 100% load.

21-03-2009, 15:44:24

Freak
ahh, then I guess you would have to look into that. Though is there much point in doing that as I would have thought there would be little difference.

21-03-2009, 19:20:09

FarFarAway
Nice review mate and seems a great PSU to power pretty much any modern rig with
Reply
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