be quiet! Pure Power 9 600W PSU Review

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be quiet! released the updated Pure Power 9 series that consists of four semi-modular models with capacities ranging from 400W to 700W. Today, we're looking at the 600W implementation to see where it stands in the competitive mainstream market.

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Pros, Cons And Final Verdict

be quiet! trusted FSP, its favorite OEM, once again and the outcome is its fresh Pure Power 9 line. Compared to the previous generation, these new models offer several upgrades. The most notable is the 80 PLUS Silver efficiency, of course. Although be quiet! claims that these units have independent regulation on all rails, our test results prove otherwise. So, if you apply full load at +12V and minimum at 5V, the +12V ripple goes out of spec due to some high spikes. With minimum load at +12V and maximum at 5V, ripple suppression might fall within the limits, but load regulation goes haywire with the voltage at +12V reaches close to 13V! Although be quiet! might claim this unit is Haswell-ready, according to Intel's compatibility guidelines for the C6 and C7 sleep states it's not. Granted, Intel's test methodology for Haswell compatibility takes the most extreme scenarios into account. This PSU probably wouldn't have a problem with newer CPUs, and you can always disable C6 and C7 if you did run into any problems.

More concerning to us is this PSU's low-quality bulk cap. We can't help but wonder why be quiet! chose to offer extra bells and whistles, like the stealth ribbon cables, instead of investing in a higher quality cap in the APFC converter. Even lower-end PSUs have 105 °C bulk caps nowadays.

At least the electrolytic caps on the secondary side are rated at 105 °C and provided by a decent manufacturer (Teapo). We couldn't expect Japanese caps inside this PSU, however Teapo has proven to be the next best choice so far. Some of you might not like the CapXon polymer caps. But solid caps are much more reliable than electrolytic ones, and on top of that, these caps are installed in a non-critical area where the applied stress is low.

To sum up, two things are way off in this PSU: performance with highly unbalanced loads and the 85 °C bulk cap. On the other hand, you get high efficiency for a Silver-rated power supply, quiet operation, compact dimensions, two native cables and a reasonable price that we expect to drop even more once the Pure Power 9 lands in the U.S.

As for the Pure Power 9 as a line-up, it's fine for mainstream and mid-level systems. The competition is tough though, and there are some offerings close to this price range with Gold-rated efficiency.

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Aris Mpitziopoulos is a Contributing Editor for Tom's Hardware, covering Power Supplies.

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Aris Mpitziopoulos
Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.

14 Comments Comment from the forums
  • turkey3_scratch
    Really poor unit. For one thing, the crossload performance is poor. Sleeve bearing fan with less reliability. 85C primary capacitor. Once again, another failed 3.3V transient response. Very high inrush current. Also, near worst of all, 140+mv of ripple on the 12V rail in CL2. Just really bad. And CL2 is a realistic scenario these days because those 3.3V and 5V rails don't do much anyway. FSP's soldering is clearly not the same as the nice soldering on their high end units.

    But my largest complaint would have to be voltage regulation (line regulation) under different load scenarios on page 6.
    Reply
  • 4745454b
    85C main cap doesn't bother me that much. It should get airflow from the fan so unless the fan dies (and if it does 105C cap isn't going to help much.) or it gets clogged with dust you should be ok. As for the CL test what do you expect? It's a group regulated design so that's going to happen. It's like buying a super duty truck and then complaining you don't get 30MPG in town. What I find more bothersome is they can't seem to sell you what they claim on the box. If it's not C6 or C7 ready and not a group reg design, why claim so? I wonder if they shipped the wrong unit?
    Reply
  • powernod
    Outstanding review by Aris as always! :)
    If only the PSU itself was outstanding as well:ouch:
    Reply
  • basroil
    Looks like FSP is still mostly a second tier manufacture with those transient response and inrush... does it really hurt that much to put a shuntable thermistor like Seasonic and SuperFlower units have?

    For less than $10 more you can usually find excellent Seasonic and SuperFlower Leadex Gold units, which makes it really hard to say this PSU is anything more than "meh"
    Reply
  • Aris_Mp
    actually I am worried about the bulk cap, because 85C means that it has 4x times lower lifetime than a 105C cap.
    Reply
  • turkey3_scratch
    17839248 said:
    85C main cap doesn't bother me that much. It should get airflow from the fan so unless the fan dies (and if it does 105C cap isn't going to help much.) or it gets clogged with dust you should be ok. As for the CL test what do you expect? It's a group regulated design so that's going to happen. It's like buying a super duty truck and then complaining you don't get 30MPG in town. What I find more bothersome is they can't seem to sell you what they claim on the box. If it's not C6 or C7 ready and not a group reg design, why claim so? I wonder if they shipped the wrong unit?

    Not all group regulated designs are exactly the same way. We see in Seasonic's S12ii series a group regulated design that actually crossloads very well. This seems to be one of the worst on the ladder.

    @Aris: Why is Inactive PWR_OK to DC_LOSS better at a higher value? Once the PWR_OK signal is dropped, wouldn't you want the unit to shut down as quickly as possible, not prolong it?
    Reply
  • powernod
    It was already explained by Aris at his review:
    "The power-good signal lasts longer, so when it drops, the voltage level of the +12V rail is already below 11V."
    When the pwr_ok to DC_loss is higher (*meaning that it has a positive , not negative value) that means that the motherboard will already have been shut-down. (*from what i've understand, at least)
    Reply
  • turkey3_scratch
    Not sure how the motherboard could shut down before the PWR_OK signal is dropped.
    Reply
  • Aris_Mp
    the problem is that in some PSUs, PWR_OK, which informs the mainboard when it should shut down, drops after and not before the rails go our of spec. So once it drops the rails are already too low.

    Normally when AC is removed, the PWR_OK signal should be de-asserted at least 1ms before voltages go out of spec in order not to stress the VRMs of the mainboard and of other components (e.g. VGA, HDD, SSD, etc.).

    The only way to address this issue is to have a circuit on the mainboard checking the input voltages and give the shut down order when these go out of spec. In other words to completely bypass the power_ok signal coming from the PSU. But this will cost money and after all a PSU oughts to follow ATX spec's guidelines.
    Reply
  • turkey3_scratch
    So is "DC_LOSS" considered "voltages out of spec"? I mean, there can still be DC even if voltages are out of spec. It won't be a loss of DC< just an out-of-spec voltage relative to the DC.
    Reply