NesteQ ASM Xzero 500w review - Testing
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Tuesday, 21 July 2009 17:35
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NesteQ ASM Xzero 500w review
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Power supply testing methodology

  • For testing power supplies I am using a homemade tester that consists of multiple power resistors and amperometers.
  • This allows me to control with pin point accuracy the exact load at each rail
  • One more reason to test psu's with this method is that high power power supplies(800+ watts) are very difficult to be tested with a normal system.With the tester I am using I can achieve loads of up to 1800 watts.
  • Readings are taken with a high sensitivity digital multimeter, and if required a voltage drop diagram is made.
  • In order for a test to be considered successful the psu has to be able to perform it for 2 hours.
  • Noise levels are recorded from 10cm away from the back of the psu(air exhaust) 

TESTING Part 1st (Real testing)

At this part the NesteQ ASM Xzero 500w will be tested in real conditions, in my pc that was built for this reason.


  • CPU:Intel core i7-950 @ stock speed
  • Mobo:EVGA X58 Sli
  • VGA:Dual MSI GTX 260@ Sli(Only one vga was used for this review)
  • Memory:Adata 6Gb kit
  • HDD: 4x Seagate 500Gb

This system is able to draw about 500w, so it will push the NesteQ ASM Xzero 500w to its limits.All reading were taken with a high sensitivity digital multimeter.In order to achive max load several instances of Orthos were running,with Furmark to stress the vga cards.Below we can see the results.





The NesteQ ASM Xzero 500w remained very silent at idle and most of the time the fan was not working, but at load the noise was higher and fan was working almost all the time but at low-mid speed.This is normal because a 500w psu is not intended for a computer like this and is really pushed to its limits.The psu had also some slight voltage drop, but it was normal and nothing to worry about.


TESTING Part 2nd(Synthetic testing)

At this part my homemade psu tester is used.This allows me to know the exact load of each rail.This is very usefull because I can measure the efficiency and also see if the psu can really provide the specified wattage.

Please note that synthetic testing is much more difficult for the power supply, and this means that it has more voltage drop than with the same load at a real system. 

Here are the results:


Part 1 - 30% load

 Voltage Line
Power Load(Amps/Watts)
 3.3v 6A/19.8w3.32v
 5v 6A/30w 5.06v
 12v1 2A/24w 12.01v
 12v2 2A/24w 12.02v
 12v3 2A/24w 12.02v
 12v4 2A/24w 12.01v



Part 2 - 50% load

 Voltage Line
Power Load(Amps/Watts)
 3.3v 8A/26.4w 3.30v
 5v 8A/40w 4.98v
 12v1 4A/48w 11.97v
 12v2 4A/48w 11.97v
 12v3 4A/48w 11.99v
 12v4 4A/48w 11.98v



Part 3 - 80% load

 Voltage Line
Power Load(Amps/Watts)
 3.3v 14A/42.6w 3.24v
 5v 14A/70w 4.96v
 12v1 6A/72w 11.96v
 12v2 6A/72w 11.97v
 12v3 6A/72w 11.95v
 12v4 6A/72w 11.97v



Part 4 - 100% load

 Voltage Line
Power Load(Amps/Watts)
 3.3v 16A/52.8w 3.21v
 5v 16A/80w 4.93v
 12v1 9A/108w 11.91v
 12v2 9A/108w 11.93v
 12v3 9A/108w 11.93v
 12v4 8A/96w 11.92v


Part 5 - Individual line loads(each line is tested alone with the maximum specified load while the others has a load of 1A*)

 Voltage Line
Power Load(Amps/Watts)
 3.3v 24A/79.2w 3.19v
 5v 20A/100w 4.89v
 12v1 20A/240w 11.86v
 12v2 20A/240w 11.88v
 12v3 20A/240w 11.87v
 12v4 20A/240w 11.87v

*The 1A load was needed in order for the psu to work correctly.With load only to one line and others left without any load strange thinks were happening.....)



Efficiency is calculated by measuring the consumption of the power supply for known loads.





Here exhaust air temperature was measured with the psu in "Manual Fan speed control" mode and the fan in the lowest rpm(~1000).  





NesteQ ASM Xzero 500w was able to withstand 500w load for 2 hours, so I raised the bars and tried to find its absolute limits...For short time it also was able to hold with 610w load, but after about 30 minutes the psu was shutting off.The max load the psu was able to withstand without failing was 530 watts.The noise was very low at all times because of the automatic fan and the high efficiency cooling system with heatpipes. We can have a look at the fan and noise testing below.


Fan speed diagram

I monitored the mosfets heatsink temperature and the rpm of the fan at the ASM mode and recorded the values. While running this test I also tried to heat the psu as more as possible in order to find the temp where the psu shuts off. It did shut off by the overheat protection when the mosfet temperature reached 80 degrees. The point where fan started spinning was at 55 degrees at the measurement point (the temp of the heatsink near the temp sensors- Click here for image).







NesteQ ASM Xzero 500w Sound pressure level

Generated sound was monitored 10cm away of the exhaust of the psu at a sound insulated box in order to eliminate any external sound or echo.Readings are taken using a high sensitivity digital SPL meter.(Values under 17dBA are considered to be inaudible)





We can see that sound levels are very low when the fan works, but at full rpm noise generated is pretty intense. In fact the only way I found to successfully reach such high temps in order to record the fan speed was by heating the power supply with a hair dryer. In a real system I really doubt if the fan will exceed 1400rpm ever.


Last Updated on Friday, 28 August 2009 14:12

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