Version 1.7 • © 2026 Hans Udo Sattler • Sattler IT-Service, Greifenstein
S-IT-SSD-Check.exe. Administrator rights are requested
automatically (they are needed for reading the values).| Button | Function |
|---|---|
| ↻ Refresh | Reads the list of connected drives again |
| ▶ Check now | Starts reading and rating the selected drive. The display fills within a few seconds. |
| 📄 Report | Saves the result as an HTML file – for keeping, printing or passing on. The report is laid out for A4; Ctrl+P in the browser with the destination “Save as PDF” produces a clean PDF. |
| Button | Function |
|---|---|
| ⚙ Settings | Everything concerning the behaviour of the program: language (Deutsch, English, Nederlands), automatic speed test, DIAG menu and the measurement history. Each area has an ⓘ with an explanation. After changing the language the program restarts. |
| 🖥 View | Everything concerning the window: display size (80 %–200 % or ↻ Automatic) and saving the window size. After changing the size the program restarts. |
| ? Help | Opens this help |
Press ESC to close the program.
All measured values at a glance, arranged in three columns:
Anyone who wants to know “is this thing broken?” looks at the third column. Values above 0 appear in red there.
The SMART values in detail, exactly as the drive reports them – for checking and for specialists.
The verdict in plain words, with its reasoning, the values it rests on and a recommendation. The rating means:
For hard disks the wording is “SMART o.k.” or “SMART o.k. – watch”, because different standards apply there (see section 4).
Checks whether the reported values fit together – see section 6.
Writes a test file to the drive and reads it back: reading with cache, reading without cache, sequential writing. “Without cache” is the realistic figure, writing the most reliable one.
Hard disks are rated by their own standard – a healthy older SSD or hard disk is simply slower by modern measures without anything being wrong. Over USB the figures are naturally lower than with a direct connection.
Shows how this drive's values have developed across earlier checks – a verdict for the whole period at the top, the values with their change below, a chart at the bottom. The tab is empty at first start and fills with every check; existing reports and DIAG archives can be imported.
Described in detail in section 7.
Five principles decide what the tool says. They are disclosed here so that every verdict can be understood – and questioned.
The remaining life quantifies only the arithmetically remaining flash life – how much of the write budget the manufacturer designed for is left. It says nothing about whether the drive is losing sectors right now. A drive can report 100 % and still be defective. Therefore the error counters count independently of the wear value: if they show a defect, the verdict is red no matter how good the wear value looks.
A red verdict needs hard evidence: reallocated sectors, pending sectors, uncorrectable sectors, reported read errors, media errors, a failed SMART self-test or spare blocks below the manufacturer's threshold. A merely low wear value does not suffice. This is deliberate: a false alarm costs a working drive.
Drives sometimes report nonsense – a write volume that is impossible in the given running time, a temperature of −128 °C, a wear value reported the wrong way round. Such values are rejected and shown as “n/a” with the reason, instead of being passed on as a figure. An honest gap is better than a confident wrong number.
Hard disks have no flash wear, so there is no remaining life in percent for them. What is rated is the actual error state – SMART status and sector values. A high running time leads to a yellow verdict, because backups matter more from then on; it never leads to red on its own.
Not every drive reports every value, and not every adapter passes everything through. Where something is missing, it says so – including why. The rating then rests on what is available, and that is stated.
| Value | What it means |
|---|---|
| Remaining life | For SSDs the key figure. Refers to the write volume the manufacturer designed for. 100 % means: practically unused. |
| Life used | The counterpart, reported by many drives directly. |
| Data written | Total amount written over the drive's life. Only meaningful in relation to capacity: 10 TB is a great deal on a 256 GB SSD and almost nothing on a 4 TB one. |
| Power-on hours | For SSDs no measure of wear – a drive can run for years without being worn. For hard disks the failure rate rises statistically with the hours. |
| Reallocated sectors | Areas the drive has replaced from its reserve. 0 on a healthy drive. |
| Pending sectors | Areas the drive could not read reliably and has marked. Above 0 means: there is data the drive cannot currently read reliably. |
| Offline uncorrectable | Areas that could not be saved even with all correction methods. The data in them is already lost. |
| Reported read errors | How often the drive was asked to read an area and could not deliver it. This counter closes a gap: a drive can only replace a bad area when it is written to again – with data that is only ever read, the reallocated count stays at 0 although areas have long stopped being delivered. |
| CRC errors | Transmission errors on the connection, not on the drive itself. The counter is cumulative and never reset, so it travels with the drive. Only a rising value indicates a current problem – then check cable, adapter or port. |
| Load/unload cycles | Hard disks only: how often the heads have been parked. Unusually frequent parking wears the mechanics; it does not enter the rating. |
| Temperature | Normal operating values are 30 to 50 °C. A warning appears above 65 °C. |
Where a value needs explaining, the tool marks it: a 1 behind a figure opens a plain-language assessment of exactly that value. The ⓘ next to a label opens the general explanation. Neither changes the verdict – they explain it.
This check compares the reported values against each other. Only a few hours of running time but sectors already replaced? Barely any operating time but terabytes written? Such contradictions point to reset counters – used drives sold as new.
A single check is a snapshot. Several checks make a history – and that answers questions a snapshot cannot.
This is not decoration; it closes a gap. In several places this program says in effect “watch for the rise” – with CRC errors, with reallocated sectors, with pending sectors. Until now it could not see the rise itself.
By default the program records the key figures with every check. It can be switched off under ⚙ Settings → Measurement history. If you do not want continuous recording, use Save this measurement now there to capture individual readings.
| Area | What it shows |
|---|---|
| Verdict at the top | The key statement across all measurements, with period and count – for instance “Unremarkable across 47 readings”. |
| Value list | For each figure the first and the current value, the change, and – in the last column – what that means. Only what the drive actually supplies is shown. |
| Chart | Draws the history of the row you click. |
The form follows the value, because the values answer different questions. The program picks it itself.
| Form | For what | What you see |
|---|---|---|
| Curve with bar | Values that inevitably run: power-on hours, data written, wear, cycles | The curve shows how steadily it goes; the bar beside it, how far it still is to a limit |
| Timeline | Values that should stay at zero: CRC, sectors, read errors | One dot per reading. If something happened, the bar changes colour from that point – so you see at once whether an incident is fresh or long past |
| Range band | Values that fluctuate: temperature | The range the value moves in, against the program's warning thresholds |
Where a curve has a limit, an ⓘ follows the heading. Behind it is explained where the mark comes from – and that it is a warning threshold, not a failure limit.
Anyone who has used the program for a while has reports and DIAG archives on disk – every file is a measurement. Under Import old reports and DIAG archives you choose a folder; subfolders are included.
Values that do not fit the series are left out. A counter cannot get smaller, a remaining life cannot rise – such jumps come from corrections to the evaluation in earlier program versions and say nothing about the drive. At the end you are told what was skipped and why.
The history is the only thing this program produces that cannot be obtained again: a report can be printed anew at any time, a measurement from three months ago cannot.
Back up history now places a copy in the folder
_Backups next to the programs, named after tool and time.
If the program later finds an empty history although a backup is waiting
there – the situation after a reinstallation – it offers to
restore it by itself. Restoring only adds; it never overwrites.
Not every connection passes SMART commands through. What works:
| Connection | SMART readable? |
|---|---|
| SATA, directly on the mainboard | Yes, completely |
| NVMe (M.2 slot) | Yes, completely |
| USB adapter with SMART pass-through | Usually yes (e.g. JMicron, ASMedia chips) |
| Simple USB enclosures and docking stations | Often not – the adapter swallows the commands |
| USB sticks and memory cards | No, they have no SMART at all |
| RAID / Intel RST mode | Only limited data through the Windows interface |
If “No data” appears, it is worth trying another adapter or connecting the drive directly via SATA. A speed test still yields useful figures.
The 📄 Report button saves the result as an HTML file. It opens in any browser, is laid out for A4 and can be turned into a PDF with Ctrl+P (destination “Save as PDF”).
The DIAG menu is meant for testers and for the further development of this program. Diagnostic data is only ever created at your explicit request – no files are made automatically.
The result is exactly one encrypted .7z file. Send that one file to
tool-entwicklung@sattler-it.de. To view your own data:
DIAG menu → Extract DIAG archive. The encryption serves
safe transport only.
7z.exe in the program folder.
In the DIAG file itself the serial number is removed.
| File | Content |
|---|---|
S-IT-SSD-Check.exe | Main program |
smartctl.exe |
Reading program (smartmontools, GPLv2) – strictly required |
drivedb.h |
Drive database of smartctl – provides meaningful attribute names |
7z.exe |
Used to create the encrypted diagnostic files of the DIAG menu. Must be the command-line version; 7zG.exe (interface) and 7zr.exe (mini version) do not understand the required commands. |
S-IT-SSD-Check-Help.html | This help file |
S-IT-SSD-Check-Hilfe.html |
The same help in German |
sit_ssdtexte_*.scl |
Language packs. Shipped encrypted – this serves text consistency, not secrecy: texts that no longer match the values cause queries about faults that are none. German is built in and needs no file. |
S-IT-Verlauf\ |
Folder with the recorded measurements, one file per drive. Holds key figures, date and serial number. To delete, simply remove the folder or single files. |
..\_Backups\ |
One level up, shared by all S-IT tools: the backups of the measurement history, named after tool and time. |
Disclaimer.txt |
Disclaimer – please read before use |
Licenses.txt |
Licences of this program and the third-party programs used |
The program is not digitally signed – a certificate costs several hundred euros a year, which is out of proportion for free software. With SmartScreen: More info → Run anyway. The tool also requests administrator rights, which some scanners find suspicious in itself; without them the SMART values cannot be read.
The connection does not pass the commands through – see section 8. Another adapter or a direct SATA connection usually helps.
Not necessarily. Some drives do not report the counter at all, others have had it reset. If the value looks implausible next to the other figures, the Authenticity tab says so.
Either the drive does not report it, or the reported value was implausible and was therefore discarded (see principle 3 in section 4). The reason is always given.
No, and this is the most important point of the whole rating: the wear value only says how much flash life is left arithmetically. It says nothing about sector errors. If a drive is losing sectors, it is defective – regardless of how good the wear value looks. In that case the value is marked as void in the display, with an explanation.
Both read the same raw values; they weight them differently. This program follows principle 1: a proven defect outweighs a good wear value. Which value carries the verdict is stated in the Condition & advice tab.
Only if there is no backup. If the program finds an empty history at
start although a backup is waiting in the _Backups folder,
it offers to restore it by itself. It can also be done later under
⚙ Settings
→ Restore history from a backup. Restoring only adds; it
never overwrites.
Probably nothing. A history comes from checking: the first measurement is recorded at the first check, a comparison needs at least two. The tab itself says what to do. It is quicker with existing reports or DIAG archives – those can be imported, and then the history does not start from zero.
Because only it assigns a measurement unambiguously to the same device. Model and size do not suffice as soon as two identical drives are in use – their measurements would end up in one file and the history would be worthless. The files stay on your computer; the program sends nothing. In DIAG files you send to us, the number is removed as before.
Set the display size by hand in the 🖥 View menu. The setting is remembered.
Yes. The program needs no installation. Keep smartctl.exe
and drivedb.h next to it; for the DIAG menu also
7z.exe. The measurement history is then written next to the
program and travels with the stick.
On the measurement, yes; on the future, no. Every rating is a snapshot based on what the drive reports about itself. A drive can fail at any time despite good values. Backups remain essential – this is exactly where the measurement history helps: it shows whether values are moving, and in which direction.
S-IT SSD-Check is freeware. Free use and distribution of the unchanged package is permitted; the source code is not public.
| Program | Purpose | Licence |
|---|---|---|
| smartctl.exe (smartmontools) |
Reads the drives' SMART values – the basis of every rating | GNU GPL v2 www.smartmontools.org |
| 7z.exe (7-Zip) |
Creates the encrypted diagnostic files of the DIAG menu. Parts of the 7-Zip program by Igor Pavlov. | GNU LGPL www.7-zip.org |
Both are shipped unchanged and keep their respective licence. The full
licence texts are in the folder 3rd-Party-Licenses.
© 2026 Sattler IT-Service, Greifenstein •
Hans Udo Sattler •
tool-entwicklung@sattler-it.de