Overclock3D improves its PSU testing equipment

2009 - Year of the PSU!

Overclock3D improves its PSU testing equipment

Back in April of 2006 , Overclock3D embarked on it's first PSU review. Determined not to go down the "plug it in, take some readings" route, initial load testing was performed using a carefully selected assortment of high wattage lightbulbs to place heavy loads on the +12v rails. It soon became clear that this setup was far from idea with the fragility and heat of the bulbs posing serious safety issues along with a total inability to test the +3.3v and +5v rails or make small adjustments to the load settings.

This setup was quickly replaced by a series of power resistors capable of placing loads on each of the three main PSU rails (+3.3v, +5v & +12v) while also allowing load adjustments of around 5 amps on each of the rails simply by adding/removing resistors from the circuit. For almost two years this became our main testing platform with various improvements being made over time including the ability to place up to a 100 amp load across several rails along with loads of up to 40 amps on the +3.3v and 5v rails. The entire system was encased in a large steel box complete with high power fans and CPU heatsinks on each of the power resistors to help keep under control the 230°C temperatures that they could reach when not actively cooled.

Unfortunately (or maybe fortunately?) in July 2008 the cooling system in the load tester was accidentally switched off during the testing of a PSU and the entire system subsequently overheated and went 'BANG'. Since then we've avoided performing any PSU reviews (apart from the odd one or two performed at Enermax's old Milton Keynes offices) until we could obtain a professional ATE load tester that would help us take our PSU reviews to the next level. Today that very item arrived on our doorstep:

SunMoon SM-268 ATE SunMoon SM-268 ATE

SunMoon SM-268 ATE On SunMoon SM-268 ATE On

Seen above is our brand new 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 any ATX 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. When connected to a PC the SM-268 has a full software suite that can effectively remote control the unit, making fully automated testing possible while also being able to output the test results to a printer.

Of course, having only spent one day with the SM-268 so far we're still really getting to grips with what it's capable of, and with an Oscilloscope on its way down to us too, it's certainly going to be a steep learning curve. However, over the next few weeks we will perfect and document our new PSU testing procedures and begin bringing some of the most accurate PSU reviews to your screens!

Discuss this article in our forums.
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Most Recent Comments

12-01-2009, 13:13:02

Hi Guys,

Over the past couple of months we have invested quite a lot in bringing our testing systems up to the latest spec. This includes two new i7 based machines for conducting X58 motherboard and Tri-Channel memory reviews along with a Phenom II based system to bring results from both sides of the scene.

However, one area we've been lacking in since our faithful custom built PSU load tester went 'POP' is PSU reviews.

Rather than simply building another homebrew test setup, this time we wanted to take things to a professional level and join the extremely small number of websites worldwide that can perform PSU testing to such a high standard. The first part of this testing arsenal arrived today. Please say hello to the SunMoon SM-268 ATE load tester:




Capable of placing loads of over 1600w on the +3.3, +5v, +12v and standby/negative voltage rails in extremely small increments, the SM-268 will take our PSU load testing to the next level.

Complimenting the SM-268 will be a USB based oscilloscope,multimeter and thermal probe that will allow us to produce graphs for voltage stability, fluctuation and exhaust temperatures over extensive periods rather than just simply a snapshot at a particular time.

Of course we're not going to start blinding readers with science, and will instead still be producing results in formats that the average reader can understand and appreciate.Quote

12-01-2009, 13:18:19

Bout bloody time it arrived aint it .Quote

12-01-2009, 13:18:56

This is a sweet step forward for OC3D in my opinion

Readers may not appreciate this, but it's a rare thing that a review website can do their own accurate, unbiased PSU reviews.

OC3D for the win Quote

12-01-2009, 13:21:01

That is one rather mighty impressive piece of kit. I'll be eagarly awaiting any power supply reviews you have coming up.Quote

12-01-2009, 13:32:26

is that hand written on the bottom left?Quote

12-01-2009, 13:32:26

Thats well nice Jim, anyone whos anyone knew you were the psu daddy anyways.

This just put you in another league Quote

12-01-2009, 13:34:35

Just hope this does not go "POP" lolQuote

12-01-2009, 13:37:05

Originally Posted by name='chudley'
Just hope this does not go "POP" lol
That'd be a 'POP' that you'll hear clearly from Dorset Quote

12-01-2009, 13:39:14

That's an excellent piece of kit. I look forward to reading the PSU reviews now Quote

12-01-2009, 13:55:46

Should be more awesomez.

But a lot of numbers and nobs eh?Quote

12-01-2009, 14:06:19

Originally Posted by name='zak4994'
Should be more awesomez.

But a lot of numbers and nobs eh?
I feel like an old biddy trying to use a mobile phone Quote

12-01-2009, 14:14:01

WOWZER thats a pretty nice piece of kit!

i want one! (like most things i have, i don't need it i just want it )Quote

12-01-2009, 16:23:24

Looks retro in a good way like old well-built lab equipment with CROs in etc. Good stuff imo Quote

12-01-2009, 16:23:38

Few action shots of a Silverstone Zeus getting toasty with an 800w load:



17amps on +12v1

30amps on 5v

30amps on +12v2 & +12v3

28.12amps on +3.3v


...and then the voltage readings. Not bad at all 3.3v is a tad on the low side tho.Quote

12-01-2009, 16:30:25

Looks like something stolen from the Deathstar.Quote

12-01-2009, 16:30:44

Nice bit of kit. Well worth the investment IMO.

This is why we love OC3D Quote

12-01-2009, 16:35:05


12-01-2009, 16:49:27

Now I need to build a breakout board so I can hook up an extra few connectors. Anyone good at circuit board design?Quote

12-01-2009, 16:51:20

What is the board like?Quote

12-01-2009, 16:54:52

Originally Posted by name='Bungral'
Hmm I don't think I have anything more to add :')

Nice to see some tough research materials, looking forward to the 800w review already ^^Quote

12-01-2009, 17:00:04

Originally Posted by name='TonyG'
What is the board like?
Really simple to be fair. Just needs some molex and PCIE headers on it. The main problem though is carrying 30amps thru a PCB trace :sQuote

12-01-2009, 17:00:08

Didnt custompc blow one of those up they hired a long time ago.... cost them a bloody fortune to replace.. user error .

Excellent piece of kit and as someone mentioned will be great for unbaised reviews.

Bring it on Jim reviews ahoy!Quote

12-01-2009, 17:07:32

So the board is some molex to PCIE headers,its the 30amps being the big prob. Will do abit of looking around.Quote

12-01-2009, 17:18:29

Originally Posted by name='lasher'
Didnt custompc blow one of those up they hired a long time ago.... cost them a bloody fortune to replace.. user error .
Yeah they do cost a pretty penny. Thanks for the headsup...CPC can keep well away from this one

Originally Posted by name='TonyG'
So the board is some molex to PCIE headers,its the 30amps being the big prob. Will do abit of looking around.
The idea behind it is mostly to avoid me plugging PSU's directly into the load tester all the time as eventually something will break.

What i'd rather do is have a PCB full of binding posts on one side so I can connect most of the load tester outputs up to the PCB and then from the PCB have another set of molex/sata/pci-e connectors.

It will also allow me to convert that single PCI-E connector on the unit into 4 or more PCI-E plugs on the PCB.Quote

12-01-2009, 17:24:41

Some quick digging into it,the pcb track would have to be aleast 57mm wide and then it depends of the copper substrate of the pcb sheet. Would it be wiser to make a form of flylead for connecting PSU to Test Box.Quote

12-01-2009, 23:26:17

Pricey bit of kit, well over £1000? If it didnt come with a wheel at that price...


13-01-2009, 04:14:58

Originally Posted by name='fruityness'
Pricey bit of kit, well over £1000? If it didnt come with a wheel at that price...

Yeah, I could have easily bought a fairly nice OC3D company car instead :'(Quote

13-01-2009, 04:40:02

I think i have a pcb etching kit that i could have

if you would like itQuote

13-01-2009, 07:47:09

Think it would be wise to scrap the PCB idea. The tracks would not be up to those currents and anything like that would only add room for error and inaccuracy.

To put it into perspective, cooker cable that goes into the mains is 30 amp, standard mains wire is 13 amp. You would need to use the highest gague cable you can find made from the highest quality copper. High performance audio cable would be a good place to look, if you can find some in the 40amp area lol. The connectors would also have to be high quality and very well fitted. Maybe worth scouting for some choc blocks that are rated for like 100 amp and use them to make a crude but effective circuit Quote

13-01-2009, 08:26:09


13-01-2009, 08:29:06

It's jims little baby Quote

13-01-2009, 08:49:51

Originally Posted by name='fruityness'
It's jims little baby
Hell ye. Nothing quite bringing even the most beastly of PSU's to their knees Quote

13-01-2009, 16:20:17

Nice to see a PSU tester capable of taxing even the most powerful units out there. It'd be good to see a 1500W unit tested all the way. Nice bit of kit.Quote

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