What if your latest bluescreen was a hardware failure ?

OCCT is the most popular CPU/GPU/Power Supply testing tool available. Free to use for the end user, it has 13M downloads since its creation in 2003. It monitors your computer while the test is in progress, and protects your components by stopping automatically once a component reaches a critical temperature.

Download (Stable, x64) Download (latest beta, x64)

4 accurate Tests

OCCT has 4 different tests : CPU:OCCT, the historical test, very accurate, CPU:Linpack, the popular error detection tool, GPU:3D, a custom 3d test, and Power supply, that combines CPU:Linpack and GPU:3D to load your power supply.

Monitoring

OCCT will monitor your computer and present you real-time graphs showing you temperatures, voltages, fan speed, frequencies, component usage, and power comsumption during your tests.

Built-in protection for your computer

Should a component reach a critical temperature during a test (by default, 85°C), OCCT will stop itself immediatly.

Test report

At the end of a test, you will be able to save a full graphical report of what happened during the test, for diagnostic purposes

Pricing Tables

OCCT hasn't gone fully commercial !

All features, except the test report in png format, are still available in the free version !

OCCT has been around since 2003, free to use except for professionnal users. This scheme worked to the extend of covering hosting costs, and purchasing license and test hardware for developing OCCT. However, at the time i write this, OCCT has not been making a penny for its authors.

To encourage everyone to participate in the OCCT adventure, we introduced a very cheap license system so that you can show your support to OCCT.

Please review the prices below and help us in developing OCCT !

To those who donated before, HOLD ON ! We are going to review past donations and send licenses according to what you paid before, as a token of thanks !

1 Month

$1.00

4 Tests
Embedded Monitoring
Overheat protection
No waiting time

1 Year

$10.00

4 Tests
Embedded Monitoring
Overheat protection
No waiting time
Test Reports

Perpetual

$15.00

4 Tests
Embedded Monitoring
Overheat protection
No waiting time
Test Reports

Pro License

$150.00

4 Tests
Embedded Monitoring
Overheat protection
No waiting time
Test Reports
No Windows domain lock
CSV readings export

CALL FOR TRANSLATIONS

As OCCT was rewritten from scratch, we need kind souls to translate OCCT. Everyone that sends me a translation in a language not yet supported by OCCT will receive a Perpetual license for free !

How to translate OCCT

Translating OCCT is easy. First, download the english translation file : English.lang . Save it next to OCCT.exe and rename it to the language you're going to translate OCCT to.

Edit it using your favorite text editor ( i like Notepad++, but any will work - make sure you keep UTF-8 as the encoding though).

The first line says : <Language Name="English"> . Replace "English", obviously.

You'll then find the block for the language codes supported by this translation. Just list whichever language code applies to your translation. These are used by OCCT to automatically load your language file on startup, by matching this code with Windows's display language. For instance, here is the French language code list :

You'll find a list of language codes here. Look at the last column.

Then, it is just a matter of replacing every string by its translation. When you're done, start OCCT, and your translation will be available in the option menu (the gear icon). Test it, and send it to support@ocbase.com

Screenshots

FAQ

Which test is the best at detecting hardware errors ?

CPU:OCCT, Large data set, with Auto number of threads is, hands-down, what will detect CPU/Memory/Motherboard stability issues faster. Use GPU:3D DX11 and fullscreen for GPU testing, and Power supply for testing your PSU. Most errors are detected within the first 5 minutes. However, i recommend doing at least a 1 hour long test just to be sure.

Which test puts the most stress on the CPU ?

CPU:LINPACK at 90% memory is the most stressful test you'll find (use the latest version supported by your CPU - 2019 is best)

Starting at how many errors do you consider a computer unstable ?

Seriously : One.

I lost my license : how can I get it back ?

Send an email to support@ocbase.com and please give us at least a day for sending you your license back.

I am not using OCCT in a commercial or professionnal environment, yet my computer is joined to a windows domain. Can i run OCCT ?

Only the PRO version of OCCT will accept to launch on a computer joined to a windows domain. This is meant at detecting uses in professionnal and commercial environment, as they heavily rely on Windows domain. In the past, as there are enthousiasts that have a Windows domain at home, we offered a way of disabling this check as they were indeed not in a commercial environment, but this saw too much abuse. About 90% of the requests were from people trying to avoid the PRO license entirely. We thus removed that possibility, and you indeed need a PRO license now to run OCCT on a computer joined to a Windows domain.

Changelog

Version 5.2.0.beta3

CPU:OCCT : Better Small data set
CPU:OCCT : Adjusted Medium and Large data set boundaries

Version 5.2.0.beta2

CPU:OCCT : Fix Medium and Large data set not starting on some instruction sets

Version 5.2.0.beta1

CPU:OCCT : Huge update to the test
CPU:OCCT : Much better AVX2 and AVX512 support
CPU:OCCT : Small data set is much more efficient and surpasses even Linpack
CPU:OCCT : Better support for high number of cores
CPU:OCCT : User can select which AVX instruction set is used

Version 5.1.0

CPU:LINPACK : Better handling of "use logical cores" and simpler startup
CPU:LINPACK : Test is now more optimized optimized, Check it out !
GPU:3D DX11 : Test has undergone a huge update in this version
GPU:3D DX11 : Higher load on the GPU
GPU:3D DX11: FPS limit now works again
GPU:3D DX11 : added back sensor display
GPU:3D DX11 : Fixed mouse cursor displaying in fullscreen mode
GPU:3D DX11 : removed dependencies to old DLLs
GPU:3D DX11 : Fixed error detection algorithm on some Quadro GPU
GPU:3D DX11 : Fixed a rare bug where GPU:3D could fail to start
GPU:3D DX9 : Removed
UI : Fixed a few typos
UI : Number input checking much improved
UI : Fixed a bug where duration > 24 hours where not fully displayed in remaining time during a test
UI : Fixed a crash when right-clicking the title bar. Silly me.
UI : While OCCT is running, computer sleep (both screen and system) should be prevented
Translations : Removed unused strings and update to language files
Added Czech translation (Thanks Jaromir !)
Added German translation (Thanks Jürg !)
Added Italiano translation (Thanks Jaroslaw ! )
Added Polski translation (Thanks Dendari ! )
Added Romanian translation (Thanks Doruletz !)
Added Ukrainian translation (Thanks Arefiev !)
BIG THANKS TO PHOBOS !

Version 5.0.1

Fixed an issue with CPU:OCCT small data set not performing as expected
Fixed an issue with CPU:OCCT not counting the cores properly in auto mode
Fixed a display issue with the number of cores used in CPU:LINPACK (it was a display issue only)
Fixed the overheating detection taking into account all sensor, not only enabled ones
Fixed the "Test progress" sentence not translating
Added Spanish language (Thanks German !)
Added Slovenian language (Thanks Jadran !)
Added Portugues language (Thanks Maxence and his girlfriend !)
Updated Russian language (Thanks Konorimci !)

Version 5.0.0

Complete UI rewrite ( material design )
Updated all tests to count the number of errors instead of stopping at the first one
Updated monitoring engine
Updated Linpack with a 2019 version
Reimplemented most things
Features are too numerous to be listed here - it is a complete reboot of the program