![[H]ardOCP](/images/blank.gif){kind=small}
- Date:
- Wednesday, November 12, 2008
- Author:
- Paul Johnson
- Editor:
- Kyle Bennett
- Google +1
OCZ 700W ModXStream Pro Power Supply
700 watt power supplies are easy to build right? Not really. These “middle of the road” units not only have to put out a lot of quality power, but are probably the most exposed to pricing competition when it comes to big power. We put the screws to the new OCZ ModXStream.
Ripple Testing
Since voltage output is not the only concern when it comes to quality DC output we next examined the ripple and regulation characteristics of the OCZ 700W ModXStream Pro. We examine these points since unnecessary ripple can cause premature failure of sensitive components in a number of different PC subsystems.
The DC output quality was logged via our digital oscilloscope and the EasyScope II software package. Each divider horizontally represents 2ms while each divider vertically represents 0.05v or 50mv. The ATX specification states that a unit should remain at or below 120mV of ripple and noise on the 12v rail while under 50mV on the 3.3v/5v rails.
Control Test Graphing
This image is the blank background control test on an unused connector from our SM-8800 during the OCZ 700W ModXStream Pro testing. This lets us determine what the background noise looks like during testing. If at any time a trace deviates from this reading that is the noise/ripple being logged by the oscilloscope for that rail. As you can see the trace is flat and shows as a blue line obscuring the axis. If during a test the axis becomes visible but a waveform is hard to discern it is most likely due to the amplitude of the trace being small in relation to our voltage divider.
100v and 120v
Test #1 is equal to approximately 25% of the rated capacity of the OCZ 700W ModXStream Pro at 45c. This makes Test #1 equal to 169w by loading the 12v rails to 11a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.5a. The results of Test #1 are good all around with the 12v rails peaking at ~25mV of ripple/noise while the 5v is peaking at ~10mV and the 3.3v is peaking at ~15mV. These results occur at both input voltages and are good but the load is still very light.
Test #2 is equal to approximately 50% of the rated capacity of the OCZ 700W ModXStream Pro at 45c. This makes Test #2 equal to 343w by loading the 12v rails to 23a, the 5v rail to 7a, the 3.3v rail to 5a, the +5vsb to 2a, and the -12v to 0.5a. Test #2 sees the amplitude of the 12v traces more than double along with the doubling of the load to a peak value of ~55mV. The minor rails have also increased with the 5v rail hitting 25mV and the 3.3v rail peaking at ~20mV.
Test #3 is equal to approximately 75% of the rated capacity of the OCZ 700W ModXStream Pro at 45c. This makes Test #3 equal to 512w by loading the 12v rails to 44a, the 5v rail to 12a, the 3.3v rail to 9a, the +5vsb to 2a, and the -12v to 0.5a. Test #3 once more sees across the board increases in the amplitude of traces. The 12v rails are now peaking at ~70mV while the minor rails are peaking at ~35mV for the 5v and ~20mV for the 3.3v.
Torture Test
The Torture Test is equal to approximately 80% of the rated capacity of the OCZ 700W ModXStream Pro at 45c. This makes the Torture Test equal to 555w by loading the 12v rail to 37a, the 5v rail to 13a, the 3.3v rail to 10a, the +5vsb to 2a, and the -12v to 0.5a. The results from the Torture test are a carbon copy of those from Test #3. The peak values on the 12v rails are once more ~70mV while the minor rails repeat their Test #3 results of ~35mV (5v) and ~20mV (3.3v).
DC Output Quality Summary
The overall DC Output Quality for the OCZ 700W ModXStream Pro was acceptable for all tests completed. The peak values of ~70mV on the 12v rails were right in line with what we have been seeing from FSP Epsilon based power supplies in the 700w range such as the SuperTalent Atomic Juice PS-700. Unfortunately however, none of those FSP Epsilon based units we have reviewed to date have been award worthy for various reasons and going in to testing we were optimistic that the OCZ 700W ModXStream Pro would do better. As it stands, the OCZ 700W ModXStream Pro is not an Epsilon but on a lot of fronts today it performed very similarly to that platform, including its DC Output Quality. In the end, while in specification the OCZ 700W ModXStream Pro was not the cleanest unit we have ever seen in its DC Output Quality through 75% output. However, we don't know what the units DC Output Quality looks like at full load since both units failed to do full load in our test environment so it is hard to call this test a pass across the board.