Transient Response
Transient response in power supplies refers to how quickly and effectively the PSU stabilizes its output voltage during sudden changes in load demand, such as when a CPU or GPU increases its power draw. It’s measured by the time and voltage deviation during these shifts. A faster, smaller transient response ensures stable power, preventing instability or damage to components.
20% Load – 20ms
| Advanced Transient Response 20% - 50 Hz - No Caps | ||||
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.106V | 11.862V | 2.02% | Pass |
| 5V | 5.005V | 4.909V | 1.92% | Pass |
| 3.3V | 3.300V | 3.184V | 3.53% | Pass |
| 5VSB | 5.088V | 5.045V | 0.85% | Pass |
50% Load -20ms
| Advanced Transient Response 50% - 50 Hz - No Caps | ||||
| Voltage | Before | After | Change | Pass/Fail |
| 12V | 12.076V | 11.984V | 0.76% | Pass |
| 5V | 5.001V | 4.901V | 2.00% | Pass |
| 3.3V | 3.298V | 3.177V | 3.67% | Pass |
| 5VSB | 5.046V | 5.000V | 0.92% | Pass |
The transient response is average at 12V, primarily because of the significant deviation during the first test, where the PSU’s resonant controller focuses on efficiency and not on transient response. The 5V and 3.3V rails have low deviations, but the second rail’s low nominal voltage doesn’t allow above 3.2V voltage levels when the transient loads are applied.
Transient Response ATX v3.1 Tests
For PSUs without a 12+4 pin connector, the maximum applied load for the transient response tests is 150%, rather than 200%.
The PSU passes all ATX v3.1 transient response tests.
The 12V rail’s performance is satisfactory in these tests.
i was able to get this thermalright TR KG850 on sale for $36, i was wondering how bad it would be if i used a 300W GPU (9070 XT hellhound OC) since the cables are only 18AWG.
PS: and I’d like to humbly request that someone could test this PSU as I havent found anyone. it came out in 2025, and has a 5 year warranty.
even more interestingly a better PSU, TR-AG850 has a 10 year warranty which may be a competitor at the high end of PSUs.
Unfortunately, I cannot get my hands on TR PSUs. With the first chance, sure I will test them!
thanks! I’ve just emailed Thermalright recommending them to contact you, not sure if that’s how it’s supposed to work but hopefully they follow up.
Thx aris for a review, btw do you have any Cybenetics updates for XPG Pymcore series can’t wait to see the internals ?
No yet, sorry.