Stability test · RAM
RAM stress test.
TestMem5 style patterns with the 1usmus v3 configuration, on almost all free memory locked in RAM. Built for checking XMP, EXPO and every timing change. Four profiles, including ones for Ryzen X3D and Intel’s memory controller.
- 1 min to 1 h for free
- No time limit in PRO
- Free memory checked every 2 s
Memory slices, one per thread
An illustration. The real window shows threads, gigabytes checked, the current pattern and finished phases.
What the test does
Write, read and compare every word.
From the 1usmus v3 configuration we took the list of tests, their order and parameters. The implementation is our own and nothing from TestMem5 is included. Every chunk is checked right after it is written.
Moving inversions
Write a pattern, walk up writing its inverse, walk down, then read. On 64-bit and 128-bit words with different strides.
Random data and bit patterns
Seeded data that depends on the address, plus 0/1, 0x55/0xAA, walking ones and zeros, each together with its inverse.
Address as data and refresh
Every word holds its own address. The refresh test writes a slice, waits 2 s and only then reads it back.
Random jumps between blocks
Threads read random lines across the whole area, including other threads’ slices. This loads the memory controller.
The block is free memory minus 1 GB or 5% of RAM, whichever is larger. The pages are locked in RAM, so Windows does not move them to disk. Every 2 s the test checks how much free memory is left and halves its block below 10%.
Profiles
Four profiles, one for your CPU.
The app suggests a profile based on your processor name, but the choice is always yours.
Standard
The order and parameters from 1usmus v3. A good start and right for most PCs.
X3D
256 MB chunks and writes that bypass the cache. The large L3 of Ryzen X3D then does not hide RAM errors.
Intel
Focus on the memory controller: large strides, random jumps between blocks, address as data and refresh.
Extreme
The heaviest: test order and time share modelled on the PCBdestroyer configuration. For a long run after overclocking.
When to use it
Memory fails quietly.
Unstable RAM rarely gives one clear symptom. More often it is random crashes, corrupted files, errors while unpacking and games that drop to the desktop once every few hours.
After turning on XMP / EXPO
A vendor profile is overclocking too. Not every memory controller in a CPU holds it without errors.
After timing changes
After every tighter timing or higher speed. Short at first, long at the end.
New sticks or more modules
Four modules load the controller harder than two. The same kit can be stable with two and not with four.
Crashes and corrupted files
Random errors in games, while compiling shaders or unpacking. The test helps check whether memory is to blame.
After a BIOS update
A new BIOS changes memory training and voltages. You can read timings and XMP / EXPO in the BIOS tab.
Together with the CPU test
Sorting errors in the CPU stress test can come from memory or its controller.
How to read the result
What a memory error means.
No error in the gigabytes checked and no WHEA event in the Windows log.
The report gives the test, the thread, the position in the block, the expected and the read word, and the number of bad bits.
You stopped the test, the CPU hit 95 °C, a laptop switched to battery or free memory ran out.
- Single bad bitsA typical sign of timings that are too tight or voltage that is too low. Undo your last change.
- Errors only in random jumpsThese point more to the memory controller than to the sticks. Try the Intel profile or a lower speed.
- An error in the refresh testData disappears after a few seconds without access. Usually a matter of the memory refresh timings.
- Many errors from the first minuteThe settings are far from stable or a module is faulty. Check the memory at default settings.
To be honest: a test inside Windows cannot see memory used by the system and other programs, nor physical addresses. For a full check of the sticks, for example before a warranty claim, use a tool that boots from a USB drive. For checking XMP, EXPO and timings after each change, this test is simply more convenient.
Questions
FAQ
How much memory does it test?
Almost all free memory: free memory minus 1 GB or 5% of RAM, whichever is larger. The pages are locked in RAM, so Windows does not move them to disk during the test.
Which profile should I pick?
Standard to start. X3D for Ryzens with a large L3 cache, so the cache does not hide RAM errors. Intel stresses the memory controller. Extreme is the heaviest set for a long run after overclocking. The app suggests a profile for your CPU.
Does this replace MemTest86?
Not entirely. A test inside Windows cannot reach memory used by the system and other programs. For a full check of the sticks, use a tool that boots from a USB drive. The SmoothWizard test is handy for checking XMP, EXPO and timings after each change.
An error showed up after a few minutes. What should I change?
Go back to your last stable settings, or loosen the timing you changed last or lower the memory speed by one step, then test again. Change voltages only within the range recommended for your platform.
Why does the PC slow down during the test?
The test takes almost all free memory. Every 2 seconds it checks how much is left and halves its block below 10%. Better not to run games or a browser with many tabs at the same time.
How long does the test take?
From 1 minute to 1 hour in every version of the app. With no time limit, until you stop it (24 hours at most), in PRO.
XMP on? Check that it holds.
The RAM stress test is in the Benchmark tab in SmoothWizard. 1 minute to 1 hour in every version, with no time limit in PRO.
