Gigabyte Xtreme Gaming 1200 W 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 PSU's response in two different scenarios. First, a transient load (10 A at +12V, 5 A at 5V, 5 A at 3.3V and 0.5 A at 5VSB) is applied for 200 ms while the PSU works at 20 percent load. In the second scenario, the XP1200M is hit by the same transient load while operating at 50 percent load. In both tests, we use our 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 tests "Advanced Transient Response Tests," and they are designed to be very tough to master, especially for a PSU with a capacity of less than 500 W.  

Advanced Transient Response at 20 Percent

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.297V12.170V1.03%Pass
5V4.955V4.853V2.06%Pass
3.3V3.301V3.150V4.57%Pass
5VSB4.936V4.871V1.32%Pass

Advanced Transient Response at 50 Percent

Swipe to scroll horizontally
VoltageBeforeAfterChangePass/Fail
12V12.228V12.096V1.08%Pass
5V4.917V4.815V2.07%Pass
3.3V3.272V3.130V4.34%Fail
5VSB4.892V4.826V1.35%Pass

The transient response performance of the +12V rail looks fair. However, in this high-end category we are only satisfied with lower than 1% deviations, and the ideal scenario is close to 0.5% voltage drops. The 5V and 5VSB rails perform quite well, while the 3.3V rail registers bad performance with high voltage drops that lead to a failure in the second test.

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

Transient Response At 20 Percent Load

Transient Response At 50 Percent Load

Turn-On Transient Tests

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

For the first measurement, we turn off the XP1200M, dial in the maximum current the 5VSB rail can output and switch the PSU on. In the second test, we dial the maximum load the +12V can handle and start the PSU while it's in standby mode. In the last test, while the XP1200M is completely switched off (we cut the power or switch the PSU off by flipping its on/off switch), we dial in the maximum load the +12V rail can before switching the PSU 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 12 V is 13.2 V, and 5.5 V for 5 V).    

The 5VSB rail performs fine, and in the second test the +12V rail's slope looks pretty good. The commendable performance doesn't continue through the last test, where the +12V rail's voltage makes several waves before it settles down to its nominal voltage. 

Aris Mpitziopoulos
Contributing Editor

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

  • turkey3_scratch
    Yawn. It's loud. Might not be too loud in most people's cases where the unit is sucking cool air from underneath the computer, and where they overestimate their power requirements, but it's still way too loud. If they're going to make the fan that aggressive, they should give it a longer warranty. Give it an ol' 11 year warranty to beat the competition at least.

    The only way Gigabyte is going to sell this at whatever price is if they do some marketing. "Nvidia Gigabyte GPUs work best with Gigabyte PSU" and people will buy it.
    Reply
  • powernod
    Enhance continoues its mediocre performance!!
    The only series i can remember, in which Enhance showed some very good results were the Thermaltake's GRAND Platinum line.
    Besides that,..... just mediocre !!
    Reply
  • Vorador2
    When i saw that it used the word "xtreme" (ugh) and "gaming" together in the name of the product i knew it was going to be either overpriced or underperforming. Or both.
    Reply
  • DotNetMaster777
    Built by enhance electronics but only five years warranty !
    Reply
  • Sam Hain
    In the 1.2kw range... The EVGA SuperNOVA 1200 P2 is a great buy @$230 (or so), awesome specs and performance across-the-board and some of the highest customer ratings to back it's build quality.

    Reply