Final Words

Compared to former power supplies from Silverstone we can say that the company made an aggressive but logical step forward. With 650 watt it is one of the higher performing power supplies and therefore not suiting every users needs. With an efficiency of over 80% at lower loads (with 230VAC) it could run a decent medium class PC without wasting too much energy.

Due to the increasing temperature of our tests, we saw the voltages drop, especially on the lower voltage rails. The chosen high-end components have been a good fit for the most part but heat is still an issue. The new crew of engineers has come up with a good PCB design as well. From the high overall quality, one can literally see the robots installing these components.

The heatsinks have a very clever shape to let much air through to the PCB to cool down most of the components where they stand. They have a decent thickness as well which allows for a lot of heat conduction. The temperature of the heatsinks was average but we have seen colder ones. As for fan speed, the produced noise level was not the best result we could have hoped for, but it seems to be necessary to cool down the power supply to keep it working properly. We would love to see Silverstone take a second look at the fan speed and adjustments. The sound issue shouldn't be a real problem for most users who chose this PSU, as they will not be able to load the PSU anywhere near 80%. Not many people will ever hear this power supply with full load.

Protection features work fine in this model. The power supply correctly shuts down with any potential threat to its life such as over current or over power. Our short circuit test on each line during different loading stages had a positive outcome too with no damage to our unit.

In case of efficiency the OP650 has surprised us in a good way. At 230VAC it reached 80% efficiency with the impressively low load of 20%. At a medium load we saw an impressive 83% efficiency which held on until our highest load tests. At the lowest input of 115VAC we could only reach an efficiency of 81% which is still a very good result. In case of standby efficiency we measured just about 1.19W at 115VAC and 1.7W at 230VAC which is not a very high energy loss: exactly what we would like to see.

The price of the OP650 is just about $160 in the United States and around 139€ in Europe which is a reasonable price for a 650W power supply. It is a good price for the quality and performance this power supply brings to the table.

The build quality of the Olympia series is unmatched from other series of Silverstone PSUs which makes it the highest performer the company offers. We are looking forward where this leads in the future and what power supplies Silverstone will put out next.

Acoustics
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  • YellowWing - Friday, July 13, 2007 - link

    In a prior article you showed us the box you use for testing power supplies. I don't remember reading how the heat generated by the power supplies is removed from the sealed box. Does the temp of the air in the box rise with time? Would the drop off in voltage be less with full ventilation?
  • YellowWing - Friday, July 13, 2007 - link

    Brownouts have caused power supply failures for me in the past. How about dialing the input voltage down to 90 or so and see what happens.

    From experience I can say that some supplies don't survive at lower input voltages.
  • DerekWilson - Friday, July 13, 2007 - link

    we are considering looking at 90V input. Thanks for the suggestion.
  • bpt8056 - Friday, July 13, 2007 - link

    I just want to say that I thought AT did a great job on the review. Keep up the great work!
  • puffpio - Friday, July 13, 2007 - link

    Great article..looking forward to many many more

    On one of the graphs of the 230V tests, it is labeled as 115V
  • jonnyGURU - Friday, July 13, 2007 - link

    Good job. Clearly a lot of effort was put behind putting the methodology and this review together.

    Couple questions..

    1. How much of the voltage drop shown would you contribute to the resistance created by the interface board and wires located between the end of the PSU's connector and the actual load. This isn't my favorite power supply, but I know the voltage regulation isn't nearly as bad as you have it graphed. And naturallly, since load also creates resistance, your voltage is going to decrease exponentially if you're not loading and measuring at the end of the connector. Since you're using a Chroma, I know you're not loading and measuring at the connector. Perhaps you could rig a DMM to measure voltages at the end of the connector instead of reporting what the Chroma is telling you since the Chroma is going to be incorrect since it doesn't take into consideration this added resistance.

    2. Do you think it's possible to define "10%, 20%, etc." as it pertains to your loads. Naturally, you can't load all rails by 80%, 90%, 100%" because you'd easily exceed the power supplies capabilities. And certainly you're not loading the +12V with 80%, 90% 100% and then filling up the remainder with a 3.3V and 5V load because then you would crossload the PSU with an unusually high +12V load.

    3. And, at risk of sounding like I'm beating a dead horse, ripple and noise results. We all know spec is 1%, and ripple and noise does typically increase with load. It would be nice to see if the power supplies being tested stay within that spec. through out it's total advertised capability.

    Thanks and I look forward to the next PSU review!
  • mcvan - Saturday, July 14, 2007 - link

    Like Johnny said. ;)

    Another issue pertinent to the extreme sag in voltage lines and perhaps to the soaring temperatures is to ask how long the PSU was run at each load level (and in total) and what was the air temperature at the PSU intake? Maybe the test box is just letting the PSU get way too unnaturally hot, and this has a deleterious effect on performance. This test box is not the same as thermal control chamber where you can dial in a specific target temperature, which will then be held constant by the chamber throughout the testing.

    Since the test box is well insulated and sealed, there is a direct correlation between time spent with the PSU on and internal air temperature. No matter how the PSU is cooled, at any load, the temperature of the test box should rise continuously (even if only incrementally at very low load) as long as the PSU is running. This is a significant uncontrolled and unreported factor. That PSU intake temperature will be dictated by a complex mix of factors, by too many variables --

    -starting ambient air temp in the box
    -how long the PSU is kept running in the box and at which loads
    -heat loss out of the box
    -efficiency curve of the PSU
    -fan and fan controller characteristics

    If the time spent at each load and the starting ambient temp is kept the same for each and all PSUs, then the variables are correctly contained to the PSUs being tested. Then differences in the air temperature at the intake at any given power level for each PSU would reflect real differences in the cooling system and efficiency of each PSU. It would ensure a more level thermal playing field.
  • qpwoei - Friday, July 13, 2007 - link

    quote:

    And, at risk of sounding like I'm beating a dead horse


    While we're beating dead horses, I'll land a few blows on the dynamic load response horse as well :)
  • SilthDraeth - Friday, July 13, 2007 - link

    Seems like you know what you are talking about. I hope they take some of your points into consideration, since they all seem very valid.
  • jonnyGURU - Friday, July 13, 2007 - link

    Thanks. But I'm just an old hack. ;)

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