Riotoro Onyx 650W PSU Review

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Transient Response Tests

Advanced Transient Response Tests

For details on our transient response testing, please click here.

Ιn these tests, we monitor the PR-BP0650-SM's response in several scenarios. First, a transient load (10A at +12V, 5A at 5V, 5A at 3.3V, and 0.5A at 5VSB) is applied for 200ms as the PSU works at 20 percent load. In the second scenario, it's hit by the same transient load while operating at 50 percent load.

In the next sets of tests, we increase the transient load on the major rails with a new configuration: 15A at +12V, 6A at 5V, 6A at 3.3V, and 0.5A at 5VSB. We also increase the load-changing repetition rate from 5 Hz (200ms) to 50 Hz (20ms). Again, this runs with the PSU operating at 20 and 50 percent load.

The last tests are even tougher. Although we keep the same loads, the load-changing repetition rate rises to 1 KHz (1ms).

In all of the tests, we use an oscilloscope to measure the voltage drops caused by the transient load. The voltages should remain within the ATX specification's regulation limits.

These tests are crucial because they simulate the transient loads a PSU is likely to handle (such as booting a RAID array or an instant 100 percent load of CPU/GPUs). We call these "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for a PSU with a capacity of less than 500W.  

Advanced Transient Response at 20 Percent – 200ms

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.004V11.816V1.57%Pass
5V5.017V4.919V1.95%Pass
3.3V3.308V3.194V3.45%Pass
5VSB5.037V4.995V0.83%Pass

Advanced Transient Response at 20 Percent – 20ms

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.003V11.670V2.77%Pass
5V5.016V4.917V1.97%Pass
3.3V3.308V3.154V4.66%Pass
5VSB5.038V4.987V1.01%Pass

Advanced Transient Response at 20 Percent – 1ms

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.001V11.686V2.62%Pass
5V5.016V4.920V1.91%Pass
3.3V3.307V3.156V4.57%Pass
5VSB5.040V4.990V0.99%Pass

Advanced Transient Response at 50 Percent – 200ms

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V11.968V11.783V1.55%Pass
5V4.989V4.889V2.00%Pass
3.3V3.282V3.172V3.35%Pass
5VSB5.000V4.948V1.04%Pass

Advanced Transient Response at 50 Percent – 20ms

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V11.966V11.698V2.24%Pass
5V4.989V4.891V1.96%Pass
3.3V3.282V3.145V4.17%Pass
5VSB5.001V4.948V1.06%Pass

Advanced Transient Response at 50 Percent – 1ms

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V11.966V11.714V2.11%Pass
5V4.989V4.864V2.51%Pass
3.3V3.282V3.136V4.45%Fail
5VSB5.002V4.943V1.18%Pass

The deviations at +12V aren't good. We expect to see them below 1% on good platforms. The 5V and 5VSB rails perform much better, while the 3.3V rail registers the worst performance of all, leading to a failure during our final test.

Here are the oscilloscope screenshots we took during Advanced Transient Response Testing:

Transient Response At 20 Percent Load – 200ms

Transient Response At 20 Percent Load – 20ms

Transient Response At 20 Percent Load – 1ms

Transient Response At 50 Percent Load – 200ms

Transient Response At 50 Percent Load – 20ms

Transient Response At 50 Percent Load – 1ms

Turn-On Transient Tests

In the next set of tests, we measured the PR-BP0650-SM's response in simpler transient load scenarios—during its power-on phase.

For our first measurement, we turned the PR-BP0650-SM off, dialed in the maximum current the 5VSB rail could output, and switched the PSU back on. In the second test, we dialed the maximum load the +12V rail could handle and started the 650W supply while it was in standby mode. In the last test, while the PSU was completely switched off (we cut off the power or switched the PSU off), we dialed the maximum load the +12V rail could handle before switching it back on from the loader and restoring power. The ATX specification states that recorded spikes on all rails should not exceed 10 percent of their nominal values (+10 percent for 12V is 13.2V, and 5.5 V for 5V).    

We observe good performance here with only a minor glitch: a small spike during the last test.


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Aris Mpitziopoulos
Contributing Editor

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

  • turkey3_scratch
    I don't think it's so much the aggressiveness of the fan that contributes to the noise rather than the fact that it's just a noisy fan. There are many other fans that could be spinning at equal RPM and be much quieter while providing the same amount of cooling.
    Then again, the noise should not be too severe of a deal in a computer case with other fans (such as case fans at 100% always) contributing more significantly to the net noise.

    Edit: Nevermind, dope move by me. I didn't realize the y axis started at 1400RPM, yep, that fan RPM is very high indeed.
    Reply
  • Ne0Wolf7
    20135612 said:
    I don't think it's so much the aggressiveness of the fan that contributes to the noise rather than the fact that it's just a noisy fan. There are many other fans that could be spinning at equal RPM and be much quieter while providing the same amount of cooling.

    Then again, the noise should not be too severe of a deal in a computer case with other fans (such as case fans at 100% always) contributing more significantly to the net noise.

    I agree, especially when you're like me and have six of them because you were obsessed with filling all of the fan slots on your first build (lol). When the noise finally got to me, I got creative with my intake/ output configuration, and set my PSU to ECO mode (which is no fan). The PSU started roasting, so I rebooted with the fan going and noticed no noise difference whatsoever and the PSU was much cooler (then again, my case fans are sleeve bearing, but still).
    Reply
  • turkey3_scratch
    20135670 said:
    20135612 said:
    I don't think it's so much the aggressiveness of the fan that contributes to the noise rather than the fact that it's just a noisy fan. There are many other fans that could be spinning at equal RPM and be much quieter while providing the same amount of cooling.

    Then again, the noise should not be too severe of a deal in a computer case with other fans (such as case fans at 100% always) contributing more significantly to the net noise.

    I agree, especially when you're like me and have six of them because you were obsessed with filling all of the fan slots on your first build (lol). When the noise finally got to me, I got creative with my intake/ output configuration, and set my PSU to ECO mode (which is no fan). The PSU started roasting, so I rebooted with the fan going and noticed no noise difference whatsoever and the PSU was much cooler (then again, my case fans are sleeve bearing, but still).

    I have a build with like 6 fans that gets noisy because the motherboard only supports so many fans, so I have to plug them into the PSU. But I also have a second build that is dead silent with some Noctuas, and that's the type of build I would want a very silent or at least semi-passive PSU in.
    Reply
  • Ne0Wolf7
    20135678 said:
    20135670 said:
    20135612 said:
    I don't think it's so much the aggressiveness of the fan that contributes to the noise rather than the fact that it's just a noisy fan. There are many other fans that could be spinning at equal RPM and be much quieter while providing the same amount of cooling.

    Then again, the noise should not be too severe of a deal in a computer case with other fans (such as case fans at 100% always) contributing more significantly to the net noise.

    I agree, especially when you're like me and have six of them because you were obsessed with filling all of the fan slots on your first build (lol). When the noise finally got to me, I got creative with my intake/ output configuration, and set my PSU to ECO mode (which is no fan). The PSU started roasting, so I rebooted with the fan going and noticed no noise difference whatsoever and the PSU was much cooler (then again, my case fans are sleeve bearing, but still).

    I have a build with like 6 fans that gets noisy because the motherboard only supports so many fans, so I have to plug them into the PSU. But I also have a second build that is dead silent with some Noctuas, and that's the type of build I would want a very silent or at least semi-passive PSU in.
    My ATX motherboard only has two fan headers, not sure who was in charge there, haha, but I bought two three way splitters so I could control the speeds. My side panel has two fan slots, and I can only use one of them because the CPU cooler, so I just have this lovely outlet for sound... Its really a blessing too beacsue I have two GPUs so one can never be tarved for air too much but still. A new case and fans are in my future somewhere.
    Reply
  • takeshi7
    Can you review the Rosewill Hive 750W? I got one on sale for $60 recently and there aren't any recent reviews for it, and not from any that are as in depth as Tom's Hardware.
    Reply
  • James Mason
    @takeshi7, there aren't new reviews for it because it isn't a new PSU.
    Reply
  • takeshi7
    20143641 said:
    @takeshi7, there aren't new reviews for it because it isn't a new PSU.
    It's still relevant though. Especially because it's cheaper, more powerful, and has the same 80 Plus rating as this Riotoro unit.
    Reply
  • turkey3_scratch
    20144799 said:
    20143641 said:
    @takeshi7, there aren't new reviews for it because it isn't a new PSU.
    It's still relevant though. Especially because it's cheaper, more powerful, and has the same 80 Plus rating as this Riotoro unit.

    "More powerful" can be interpreted many ways. What do you mean by that?
    Reply
  • takeshi7
    20144830 said:
    20144799 said:
    20143641 said:
    @takeshi7, there aren't new reviews for it because it isn't a new PSU.
    It's still relevant though. Especially because it's cheaper, more powerful, and has the same 80 Plus rating as this Riotoro unit.

    "More powerful" can be interpreted many ways. What do you mean by that?
    I mean 750W > 650W.
    Reply
  • turkey3_scratch
    20144901 said:
    20144830 said:
    20144799 said:
    20143641 said:
    @takeshi7, there aren't new reviews for it because it isn't a new PSU.
    It's still relevant though. Especially because it's cheaper, more powerful, and has the same 80 Plus rating as this Riotoro unit.

    "More powerful" can be interpreted many ways. What do you mean by that?
    I mean 750W > 650W.

    Eh, doesn't really mean much of anything if you ask me. It's just what they decided to rate it at. I don't think we'll ever see a Rosewill Hive review. They're older and newer units get reviewed instead.

    A high quality lower wattage power supply can be more powerful than a lesser quality higher wattage power supply.
    Reply