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GitHub
github.com › occt-power-supply-test
OCCT Power Supply Test · GitHub
May 19, 2026 - OCCT combines CPU, GPU, VRAM, and OCCT power supply test modes with OCCT monitoring graphs and OCCT error reporting exports—popular when validating new PSUs - OCCT Power Supply Test
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Steam
store.steampowered.com › app › 3515100 › OCCT
OCCT on Steam
May 14, 2026 - Graphics Card (GPU) – Push your ... by putting your RAM under heavy load. Power Supply (PSU) – Simulate extreme power consumption to assess PSU reliability...
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OCBASE
ocbase.com
OCBASE/OCCT : Free, all-in-one stability, stress test, benchmark and monitoring tool for your PC
Ocbase is the home of OCCT, the most popular all-in-one stability / stress testing / benchmarking / monitoring tool available for PC
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SharkGaming
sharkgaming.zendesk.com › hc › en-gb › articles › 10983243538962-Test-Your-PC-with-OCCT-Simple-Guide
Test Your PC with OCCT (Simple Guide) – SharkGaming Systems
March 10, 2026 - The Power test stresses the CPU and GPU at the same time to test your power supply. ... Stop the test if temperatures become too high. ... OCCT is specifically used to detect unstable hardware or temperature problems under heavy load.
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Reddit
reddit.com › r/occt › pc immediately shuts down on power test
r/OCCT on Reddit: PC immediately shuts down on Power test
June 23, 2021 -

Hi all,

I've just downloaded OCCT today after trying to find the root cause to a PC crash/restart I've been having, and now OCCT causes my PC to immediately shutdown when running Power test.
I built the PC with all new components (expect from GPU which I have since replaced and still experience the issue).

PC Specs:

Case: Phanteks P400a
Motherboard: MSI Meg Unify X570
AIO: MSI MAG 360mm
RAM: Corsair Vengeance RGB Pro 32gb (2x16gb) DDR4 3600mhz (with 2 light enhancement kits)
CPU: AMD Ryzen 9 5900x
GPU: XFX Speedster MERC Radeon 6900XT (Black edition)
PSU: CORSAIR HX1000 Modular ATX PSU - 1000 W
GPU Support: UpHere (G276ARGB)
Storage:
Sabrent Rocket Plus 1tb NVME M.2
6TB HDD and my old SSD's (500gb + 250gb)

PC Crash/Restart:

My PC randomly restarts when playing COD Warzone. I don't play many other games but often working on the PC for 9-11 hours a day before playing games and never had any issues.

This has been happening since I built the PC in December, and has happened around 6-7 times now. It's really inconsistent as to when it happens and I've not been able to pinpoint it to an exact action/scene in-game.
There was a period since perhaps late March after I changed some settings (disabled power-saving mode & turned off automatic Windows updates), but has now come back and happened twice in the last week.

I received an event log for today's crash which was:
'Event 41, Kernal Power' - "The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."

Following that information, I eventually found myself with a potential PSU issue which is where I discovered OCCT to perform some stability & stress tests, which is what's lead me here with my PC immediately shutting down when running a test.

The exact steps were as followed:

  • Downloaded & installed 'OCCT PERSONAL STABLE (x64) 8.2.1' from ocbase.com

  • Launched the application

  • Bit of navigation and research to figure out what I needed to run. No settings were changed.

  • Under the 'Test' page and 'Test Schedule' menu, selected 'Power'.

    • Instruction set = Auto

  • Selected the large red button to run the tests

  • Presented with a popup related to the Pro version and directed to a web-page to be able to continue to execute the test

  • Hit the red button again to begin the test

  • PC turned off

  • Waited patiently incase I missed a prompt/warning notifying me that the PC would turn off, but after about 5 minutes nothing happened

  • Tried to turn on the PC to no avail

  • Turned the power switch on the PSU off & back on

  • Tried to turn on the PC to no avail

  • Repeated power switch step whilst also unplugging PSU cable and then replugging

  • PC turned on as expected

If any one has the answer to the PC Crash/Restart issue then I'd happily propose to you, but mainly looking for advise and support on the OCCT issue and why it turns my PC off completely and why I have to unplug & plug PSU cable back in for it to turn back on?

Thanks in advance <3

Top answer
1 of 5
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This one's easy : a clean, instant shutdown on the power test is 99% of the time caused by a power supply that can't handle the load. Games don't load your components at 100% - sometimes it's waiting on the CPU, sometimes in the GPU, so things even out at a rough 50-70% usually ( depending on the game ). Sometimes you encounter conditions when the load will go higher - the scene to draw is simple, another process kicks in on your CPU, ... And this is when your PSU puts itself in safe mode as it detected that it couldn't handle the load. In short, you triggered a protection feature on your power supply because it can't handle the load. There're two ways of fixing this : change your power supply to a higher rated ( and known brand !) one. Another way of tackling this is to lower the power consumption of your computer : undervolting your GPU, undervolting your CPU, lowering their frequency in the process if not enough. It'll cost you some performance probably, bit at least you won't reboot. If you can afford it, I recommend changing your power supply, as it is, in my opinion, one of the most critical components of your computer. It's feeding every pricy component with power, and if it fails, there's a possibility it won't go down alone ( even if there're protections as you experience them here).
2 of 5
2
This is a dead ringer for a power supply issue... I am pretty active on the EVGA forums and Corsair power supplies not being able to deliver the advertised wattage or just having general stability issues is a fairly common problem. The issue started to show up around the launch of the 2000 series GPUs from Nvidia and than with the 3000 series launch it kicked into overdrive. Ironically the issue seems to be more of a problem with there larger more expensive "high end" PSU than there cheaper units. I believe the issue to be caused by one of two things or a combination of the two... A lot of the "higher end" PSU from Corsair including the one that you listed use a multi rail system. Without getting too technical and diving into this too far... Basically your PSU can output 1000 watts total, but since it is a multi rail PSU, lets say two rails, each rail can only output 500 watts total. If you exceed this 500 watt limit on a given rail the PSU will shut down for safety reasons. In some cases I have seen in person that the Corsair PSU just cant output there advertised wattage. It is my belief that Corsair was taking advantage of there consumer by advertising there PSU as being able to output at one wattage when the actual output capability was far less. For the most part consumers were grossly over estimating the size of power supply they needed so Corsair was able to get away with this for a long time. However when the 2000 series and 3000 series GPUs launched an actual need for these 1000 watt power supplies developed thus exposing that Corsair PSU could not deliver. It appears from looking at the Corsair website that your PSU has a switch on the back of it that will allow you to disable the multi rail functionality. Yours may or may not have this... If that is the case I would disable it and see if that resolves the issue. As far as balancing the load across the two rails you will NOT be able to do this as Corsair does not provide the consumer with the information needed to be able to do it. Even if the above corrects the issue I would advise getting either an EVGA or Seasonic PSU at some point in the future. I do not recommend Corsair PSU to anyone at this point...
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YouTube
youtube.com › watch
How to Use OCCT for Stress and Stability Testing | Test - RAM | CPU | GPU | Power Supply - YouTube
In this tutorial we will see how to install and use occt software for stability and stress testing of pc hardware components like ram, cpu, gpu , power suppl...
Published   November 17, 2025
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Linus Tech Tips
linustechtips.com › computer hardware › power supplies
Can OCCT Ruin PSU's? - Power Supplies - Linus Tech Tips
February 13, 2022 - I was reading around that OCCT 'can' ruin PSU's. Is this true? I ran a voltage power stress test on my Corsair HX1000i and noticed all my temps sky rocket lol. Ran it for 5 minutes. My GPU and CPU got real hot. I'll post the screenshots. Not sure what AVX2 is. Maybe someone can explain?
Find elsewhere
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SourceForge
sourceforge.net › projects › occt
OCCT download | SourceForge.net
OCCT
It is widely used by PC enthusiasts and professionals to push hardware to its limits and ensure reliable performance under heavy loads. OCCT offers a range of stress tests for CPUs, GPUs, RAM, and power supplies, providing real-time metrics and alerts on temperatures, voltages, and system load. OCCT (OverClock Checking Tool) is a powerful diagnostic software designed to test and monitor the stability of overclocked computer systems. It is widely used by PC enthusiasts and professionals to push hardware to its limits and ensure reliable performance under heavy loads. OCCT offers a range of stre
Rating: 5 ​
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Reddit
reddit.com › r/overclocking › help with occt (power supply test)
r/overclocking on Reddit: help with OCCT (power supply test)
June 6, 2019 -

Hi all,

I am trying to lock in my settings and stabilize my first ever overclock and have run into an issue with OCCT returning errors on a power supply test. When using OCCT 5.0.1 power supply test (2019) it returns 63 errors, but I am unsure where to start with trying to resolve them. When I run the 2012 version I do not get any errors. I have attached the results of both below, and can see there is a difference in the power graphs. Am I missing a setting somewhere where OCCT gives me more information on the errors discovered or a more detailed report? This is my first time using OCCT

2012 test results: https://imgur.com/a/ddhmWAJ

2019 test results: https://imgur.com/a/glGwxVH

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Steam Community
steamcommunity.com › discussions › forum › 11 › 4361249719400921855
Is it safe to use OCCT ? :: Hardware and Operating Systems
April 29, 2024 - So should I have gotten a new 1200 ... watt power supply? :( Hope not. My RTX 4090 recommended 850 watts. ... With that GPU + CPU + all the rest of the PC, that's like 900 Watts right there at full loads. So yea you want 1200W, not 1000 ...
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Software Informer
occt.software.informer.com › windows › system tools › benchmark
OCCT Download - Assess your system’s stability by conducting
Right from its main screen, you can monitor the results of the four main tests. First, CPU: OCCT and CPU: Linpack tests let you test your CPU. Then, there is GPU: 3D to assess the stability of the graphics card. Finally, you can also run Power Supply, which is intended to measure your power supply’s response to intensive hardware use.
Published   May 23, 2026
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Overclock.net
overclock.net › home › forums › components › power supplies
OCCT power supply test. What does it do? | Overclock.net
August 14, 2009 - It puts load on everything in your system, HDD's, GPU's, and CPU cores, basically pushes your computer to the highest power usage it will ever reach.
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Lo4d
occt.en.lo4d.com › hardware › hardware diagnostic
OCCT 16.1.8 System stress tester for Windows
Portable Mode: Run OCCT without installation. Power Supply Tests: Monitor power usage and detect defective components.
Rating: 4.2 ​ - ​ 21 votes
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Программы
softportal.com › windows › system › benchmarks, tests
OCCT Perestroika – Download
May 28, 2026 - POWER SUPPLY - combines CPU: OCCT and GPU:3D tests for a maximum load on the power supply and motherboard.
Rating: 5 ​ - ​ 1 votes
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Overclock.net
overclock.net › home › forums › components › power supplies
Occt power test instant crash | Overclock.net
July 31, 2021 - I have no issues running OCCT power test with a 5900x and 6900 XT on a 750w power supply, no you don't need a 1000w unit.
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Overclock.net
overclock.net › home › forums › components › power supplies
OCCT Power Supply Test Error | Overclock.net
This is a PSU test because supposing you have excellent individual stability for the GPU and CPU, the PSU can't power them both together reliably - maybe the ripple is increased on higher loads or voltages drop so that this endangers the stability of the CPU, GPU, or the rest of the parts. /offtopic: Furmark/OCCT GPU and Linpack are imo totally overkill for checking stability; having them both running to push the PSU is even more pointless since the PSU will never get pushed as far as that.
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BleepingComputer
bleepingcomputer.com › bleepingcomputer forums › hardware › internal hardware
Games/ OCCT PSU test rebooting PC ( PSU Problem?) - Internal Hardware
October 9, 2015 - As the title says my PC started rebooting during games, and after running many stress tests and following suggestions, I finally found a way to replicate the problem. When I run OCCT PSU stress test, my PC reboots within a second. It was unexpected since running Prime 95 together with Furmark didn't cause any reboots.
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Reddit
reddit.com › r › techsupport › comments › bxij99 › help_with_occt_errors_power_supply_test
r/techsupport - help with OCCT errors (power supply test)
June 20, 2019 -

Hi all,

I am trying to lock in my settings and stabilize my first ever overclock and have run into an issue with OCCT returning errors on a power supply test. When using OCCT 5.0.1 power supply test (2019) it returns 63 errors, but I am unsure where to start with trying to resolve them. When I run the 2012 version I do not get any errors. I have attached the results of both below, and can see there is a difference in the power graphs. Am I missing a setting somewhere where OCCT gives me more information on the errors discovered or a more detailed report?

2012 results: https://imgur.com/a/ddhmWAJ

2019 results: https://imgur.com/a/glGwxVH