# IODD TRIM Tool — English User Manual and Chatbot Knowledge Base

**Document version:** 1.0  
**Application version:** 0.4.7.3  
**Platform:** Windows 10/11, 64-bit  
**License:** Freeware

---

## 1. Purpose

IODD TRIM Tool sends SSD TRIM requests through compatible USB storage bridges. It is intended mainly for external USB SSDs whose bridge or Windows storage path does not perform TRIM automatically.

The application can:

- TRIM an entire unpartitioned device.
- TRIM only unused areas of mounted NTFS, exFAT, or FAT32 volumes.
- Automatically select a suitable path for BOT or UAS/UASP devices.
- Fall back to Windows `Optimize-Volume -ReTrim` on supported NTFS volumes.
- Inspect disk, partition, volume, and free-space information.
- Perform a destructive write/delete/TRIM/integrity test.
- Save execution logs, failure reports, free-space maps, file maps, and speed data.
- Display its interface in Korean, English, Japanese, Simplified Chinese, Spanish, German, French, or Russian.

> **Important:** TRIM makes deleted data difficult or impossible to recover. Full-device TRIM is destructive. Always identify the target disk carefully and back up important data.

---

## 2. Requirements

- Windows 10 or Windows 11, 64-bit.
- Administrator privileges.
- A directly connected USB 3.0 or newer port is strongly recommended.
- A compatible USB-SATA or USB-storage bridge using BOT or UAS/UASP.
- An SSD that supports TRIM through at least one available command path.

Run the program by right-clicking the executable and selecting **Run as administrator**.

Avoid USB hubs while diagnosing compatibility. Port color is not a reliable indication of USB version; use a known USB 3.x port and a suitable cable.

---

## 3. Essential Safety Rules

1. Confirm the disk model, serial number, capacity, PhysicalDrive number, and volume letters before starting.
2. Keep a current backup of all important files.
3. Do not write to the target volume while TRIM is running.
4. Use **Free-space TRIM only** when files must be preserved.
5. Use **Full TRIM** only on a disk whose volumes have already been deleted.
6. Do not enable **Allow system disk (DANGER)** unless you fully understand the consequences.
7. Start compatibility testing with **Dry-run** and a small **Batch run limit**.
8. Leave **UASP method (expert)** set to **Auto** unless troubleshooting a known bridge.
9. Do not disconnect the device during a successful operation.
10. If the bridge has already disappeared from the USB bus, follow the reconnect instructions shown by the program.

TRIM is not a secure-erasure guarantee. An SSD controller may retain internal copies because of wear leveling, over-provisioning, or firmware behavior. Use the drive manufacturer's sanitize or secure-erase function when certified erasure is required.

---

## 4. What TRIM Does

TRIM tells an SSD that specified logical blocks no longer contain useful data. The SSD can then reclaim those blocks during internal garbage collection.

Possible benefits include:

- More consistent write performance.
- Less internal copying of obsolete data.
- Reduced write amplification.
- More efficient garbage collection.

TRIM does not normally overwrite every byte immediately. A successful command means that the request was accepted through the selected storage path; the SSD decides when and how the underlying NAND is reclaimed.

---

## 5. Main Window

The application contains three tabs:

- **TRIM Execute** — select a disk, choose a mode, and run TRIM.
- **Drive Inspect** — examine partitions, volumes, free space, and physical layout.
- **Real Test** — write test files, delete selected files, run TRIM, and verify retained files.

The toolbar also provides:

- **IODD Products**
- **IODD Manual**
- **How to Use**
- **License**
- **About TRIM**
- Language selection

The disk list refreshes automatically after USB device arrival or removal. Use **Refresh** if Windows has just detected a device, its partitions changed, or the displayed information appears stale.

---

## 6. TRIM Execute

### 6.1 Select and verify the target

Choose a USB disk from **Disk Selection**. A list entry may include:

- `PDn`: Windows PhysicalDrive number.
- Model and capacity.
- Transport: BOT or UAS.
- Mounted drive letters and file systems.
- USB speed hint.
- `ATA-TRIM:YES`, `ATA-TRIM:NO`, or an unavailable ATA probe result.

`ATA-TRIM` describes the ATA/SAT path reported through the USB bridge. It is not a complete statement about every possible TRIM path. A UAS device may still trim through DSM or SCSI UNMAP even when ATA Pass-Through is unavailable.

The detail panel shows model, masked serial number, capacity, transport, volumes, partition offsets, file systems, and ATA probe information. ATA identity and capability results may be emulated by the bridge and can differ from the actual SSD.

When **Start** is pressed, the application rechecks disk identity and volume layout. If the disk was replaced, reformatted, or repartitioned since the last refresh, the operation is aborted and the list is refreshed.

### 6.2 Execution modes

#### Free-space TRIM only

Use this mode to preserve existing files and trim unused clusters belonging to supported mounted volumes.

- Supported volume types: NTFS, exFAT, and FAT32.
- FAT12/FAT16 volumes displayed as `FAT` are not supported.
- Only ranges proven unused by the file-system bitmap are planned.
- If no eligible volume, no free range, or no readable bitmap exists, the program stops with a reason.

This is the normal choice for a disk that contains files you want to keep.

#### Full TRIM (Entire device range)

This mode targets the whole physical LBA range and is destructive.

- It is available only when the selected disk has no volumes with drive letters.
- Delete all volumes first using Windows Disk Management or another appropriate tool.
- Existing partition tables and data may become unusable.
- The optional post-TRIM initialization can create a new GPT or MBR disk layout.

Post-TRIM initialization is skipped after a dry run, cancellation, bridge hang, or a run with no successful batch.

### 6.3 Basic options

**Dry-run (verify only, no send)**  
Builds and validates the range plan and command data without sending actual TRIM commands. It does not prove that the bridge or SSD will accept TRIM.

**Windows ReTrim only (skip DSM / UNMAP / ATA Pass-Through)**  
Skips raw hardware paths and runs Windows PowerShell `Optimize-Volume -ReTrim` directly. Use it for known incompatible bridges. This path is offered for NTFS volumes; it is not the solution for exFAT or FAT32.

**Show Advanced Options**  
Displays timeout, retry, batching, logging, flushing, and expert method controls.

**Init after TRIM**  
For Full TRIM, choose GPT, MBR, or **Do not initialize**.

### 6.4 Advanced options

**Timeout (ms)**  
Per-command SCSI pass-through timeout. The current default is 20,000 ms.

**Retry**  
Number of retries after a send failure. The default is 3.

**Batch entries**  
Number of TRIM ranges grouped into one command. The default is 32. Reduce this if a bridge rejects large payloads.

**Batch run limit**  
Runs only the first 1, 10, or 100 batches, or all batches. Use a small limit for initial hardware testing. A limited run trims only part of the plan.

**Allow system disk (DANGER)**  
Overrides the system/boot-disk safety block. This option is deliberately not saved and resets on every start.

**Mask serial in log**  
Partially hides disk serial numbers in logs.

**Exclude repetitive messages**  
Suppresses repeated per-batch informational messages. Warnings, errors, planning information, and final totals remain in the log.

**Flush volumes before TRIM**  
Calls `FlushFileBuffers` on mapped volumes before TRIM.

**UASP method (expert)**  
Available choices are:

- **Auto** — recommended.
- **SCSI UNMAP** — forces UNMAP on UAS devices. It can process FAT32/exFAT free space but may require volume lock/dismount and can destabilize fragile bridges.
- **ATA Pass-Through** — forces the ATA/SAT path.

The expert selection is not saved and returns to **Auto** at startup. A forced method takes precedence over **Windows ReTrim only**.

### 6.5 Recommended first run

1. Connect the SSD directly to a USB 3.x port.
2. Start IODD TRIM Tool as administrator.
3. Select the disk and verify all identity information.
4. Choose **Free-space TRIM only** if the disk contains files.
5. Enable **Dry-run**.
6. Open advanced options and set **Batch run limit** to `1`.
7. Press **Start** and enter the number following `PD` when requested.
8. Review the plan and log.
9. Disable **Dry-run**, keep the batch limit at `1`, and run one real batch.
10. If it succeeds without disconnecting the bridge, select `All` and run the complete operation.

### 6.6 Confirmation and cancellation

The application shows a data/lifespan warning and requires the target PhysicalDrive number to be typed manually. A mismatch aborts the operation.

**Cancel** requests prompt termination. A command already inside Windows or bridge firmware may take time to return, but bounded worker handling prevents known ATA bridge hangs from blocking the UI indefinitely.

---

## 7. How the Command Path Is Chosen

In **Auto**, selection depends on transport, mode, file system, bridge behavior, and safety guards.

- BOT devices normally rely on ATA Pass-Through.
- UAS free-space operations can attempt Windows DSM and SCSI-based paths.
- SCSI UNMAP may retry with a smaller/single-descriptor form when a bridge rejects a larger payload.
- WRITE SAME may be used as an available SCSI fallback.
- ATA Pass-Through can be attempted when appropriate.
- For an NTFS volume, Windows `Optimize-Volume -ReTrim` may be offered or selected as a safer native fallback.
- The Pinned Volume guard can intentionally avoid raw methods on some mounted UAS/NTFS paths and propose Windows ReTrim instead.

Intermediate warnings do not necessarily mean that the overall operation failed. Judge the result by the final summary:

- Successful batches greater than zero.
- Failed batch count.
- Cancelled or bridge-hang state.
- Final success/failure message.

---

## 8. Drive Inspect

Select a disk on the TRIM tab, open **Drive Inspect**, and press **Inspect**.

The tab reports:

- Disk model and capacity.
- Transport and bus hints.
- Partition number and GPT/MBR style.
- Volume letter and file system.
- Cluster and sector counts.
- Total, used, and free space.
- Physical partition start.
- Partition length.
- Free fragments and last-used/free-space information.

**Export Free Sector List** saves free-space LBA ranges for the volumes to CSV. The export is diagnostic; it does not execute TRIM.

Refresh and inspect again after formatting or repartitioning a disk.

---

## 9. Real Test

### 9.1 Purpose and warning

Real Test checks the complete write/delete/TRIM/read path using generated files. It is not required for routine TRIM and normally needs to be run only once for a particular SSD, bridge, cable, and port combination.

> **Warning:** Real Test intentionally fills most of the selected volume's free space, writes many gigabytes, deletes test data, and can take several hours. It consumes SSD write endurance. Do not use a volume that cannot safely be filled.

Test data is stored in:

`<selected drive>\trim_real_test\`

The 1 GB files are stored in its `dumy` subfolder.

### 9.2 Five-step procedure

**STEP 1 — Pre-TRIM and create 500 MB files**

- Runs free-space TRIM before file creation.
- Fills approximately one third of the available space with generated 500 MB files.

**STEP 2 — Delete selected files and TRIM**

- Deletes every tenth 500 MB file.
- Flushes the volume.
- Exports a free-space CSV.
- Runs free-space TRIM.

**STEP 3 — Fill with 1 GB files**

- Creates generated 1 GB files in `trim_real_test\dumy`.
- Continues until approximately 1 GB remains free.

**STEP 4 — Verify 500 MB files**

- Reads the retained 500 MB files.
- Regenerates the expected data stream from the path-based seed.
- Compares CRC results.

**STEP 5 — Verify 1 GB files**

- Performs the same integrity check for the 1 GB files.

STEP 4 and STEP 5 log the total number verified, passed, and failed. A missing file or CRC mismatch is logged individually. Verification continues after a failure so the complete result is available.

### 9.3 Controls

**Start Step / End Step**  
Run any contiguous portion of STEP 1 through STEP 5. The start step must not exceed the end step. Later-step runs scan existing test files when necessary.

**Target Drive**  
Selects the mounted logical volume used for the test.

**Speed drop wait (min, 0=off)**  
When the measured two-second write rate falls below 50% of the moving average, writing pauses for the selected number of minutes. Zero disables this behavior. A cooldown prevents immediate repeated pauses.

**Start TRIM Real Test**  
Starts the selected step range after confirmation.

**Verify Only**  
Scans the existing test folder and verifies the retained 500 MB files without creating or deleting data. To verify the 1 GB set, run STEP 5.

**Stop**  
Requests cancellation.

**Delete Test Folder**  
Permanently deletes `trim_real_test` and all files below it.

**Export File Map CSV**  
Saves test-file names, sizes, and physical start/end sector information.

**Speed Chart**  
Displays the last run's time-series speed data. Data can be saved as CSV.

### 9.4 Understanding verification results

- **Passed** means the file content matched the deterministic content expected for that file path.
- **CRC mismatch** means the file exists but its data differs.
- **File missing** means a file expected by the scan could not be opened or no longer exists.
- Any failure marks the step and overall verification result as failed.
- A passing Real Test supports compatibility for the tested combination, but it cannot guarantee all future behavior or prove the SSD's internal implementation.

---

## 10. Logs, Reports, and Settings

The on-screen log is also written to a file. Detailed failures can generate timestamped JSON and CSV reports such as:

- `failure_report_YYYYMMDD_HHMMSS.json`
- `failure_report_YYYYMMDD_HHMMSS.csv`

Reports include command results, Windows error codes, SCSI sense information, retries, and batch details. Common Windows storage error text is kept in English for consistent technical support across localized Windows installations.

`settings.ini` is stored next to the executable when that location is writable. It can retain language, display, execution, and Real Test preferences.

For safety, these choices are not persisted:

- **Allow system disk (DANGER)**
- A forced **UASP method**; it always starts as **Auto**

Deleting `settings.ini` restores defaults. Do this only while the application is closed.

---

## 11. Troubleshooting

### Disk does not appear

- Reconnect it directly to a USB 3.x port.
- Replace the cable.
- Remove a USB hub.
- Wait for Windows to detect the disk, then press **Refresh**.
- Very small USB candidates and devices without usable USB identification may be filtered from the list.

### Administrator privileges are required

Close the program and use **Run as administrator**.

### `ATA-TRIM:NO` or ATA Pass-Through unavailable

This describes the ATA path reported through the bridge. UAS devices may still work through DSM or SCSI UNMAP. Use **Auto** and examine the final result.

### Free-space mode is unavailable

Confirm that the disk has a mounted NTFS, exFAT, or FAT32 volume and that Windows can read its allocation bitmap. Refresh after formatting or partition changes.

### Full TRIM is unavailable

The disk still has one or more volumes. Full-device TRIM requires a disk with no mounted volumes. Delete the volumes only after backing up all data.

### Hardware paths were rejected

For NTFS, accept the offered Windows `Optimize-Volume -ReTrim` fallback or select **Windows ReTrim only**. For exFAT/FAT32, Windows ReTrim is not the fallback; Auto or forced SCSI UNMAP may work if the bridge supports it.

### The device disconnects or disappears

Some bridges become unstable after unsupported raw commands:

1. Do not use **Safely Remove Hardware** for a device that has already vanished.
2. Physically unplug and reconnect it.
3. Wait until Windows detects it.
4. Refresh the disk list.
5. Leave the UASP method on **Auto**, or use Windows ReTrim for a compatible NTFS volume.

### A warning contains `winerr=1`, `5`, or `1117`

It may be an intermediate path rejection followed by a successful fallback. Read the final execution summary. If all batches failed or the bridge disconnected, treat the run as failed.

### TRIM batches time out or fail

- Increase **Timeout (ms)**.
- Reduce **Batch entries**.
- Test with **Batch run limit = 1**.
- Try another cable, port, or enclosure.
- Return the expert method to **Auto**.

### Logs or settings are not created

The executable directory may be read-only. Move the application to a user-writable folder and run it again.

### Real Test reports CRC mismatches

Stop using that SSD/bridge path for important data until investigated. Repeat verification without writing, inspect SMART/health data with a suitable tool, change the cable or bridge, and restore affected data from backup.

---

## 12. Frequently Asked Questions

### Q: Which mode should most users choose?

Use **Free-space TRIM only** when the disk contains files. Use Full TRIM only for a deliberately emptied, unpartitioned disk.

### Q: Does Free-space TRIM delete my existing files?

It plans only clusters reported free by supported file systems. Nevertheless, back up important data because bridge firmware, hardware faults, power loss, or incorrect disk selection can still cause loss.

### Q: Does Full TRIM securely erase the SSD?

No certified guarantee is provided. It invalidates the full logical range, but physical NAND handling is controlled by SSD firmware.

### Q: Why is Full TRIM disabled?

The selected disk has a volume. Delete all volumes first if full-device destruction is intended.

### Q: What is the difference between BOT and UAS/UASP?

BOT is the older USB mass-storage transport and commonly uses ATA Pass-Through for SATA SSD TRIM. UAS/UASP is a newer SCSI-oriented transport and can use DSM, SCSI UNMAP, or other fallbacks.

### Q: Why can `ATA-TRIM:NO` still result in successful TRIM?

Because it describes only the ATA/SAT probe. UAS devices may use SCSI UNMAP or DSM instead.

### Q: Should I force SCSI UNMAP or ATA Pass-Through?

Normally no. Keep **Auto**. Forced methods are intended for expert diagnostics and known bridge behavior.

### Q: Why does Windows ReTrim work only for NTFS here?

The application uses Windows `Optimize-Volume -ReTrim` as its native fallback for supported NTFS volumes. exFAT/FAT32 must use a compatible hardware path such as SCSI UNMAP.

### Q: Is a Dry-run proof that TRIM works?

No. It validates planning and command construction but sends no command to the bridge or SSD.

### Q: Why start with one batch?

It limits exposure while checking whether the bridge accepts the command without errors or disconnection.

### Q: Is an intermediate warning a failure?

Not always. Auto mode may try several paths. The final summary determines overall success.

### Q: Can I cancel safely?

The program supports cancellation, but a command already being processed may not stop instantly. Avoid disconnecting a device that is still responding.

### Q: How often should I run TRIM?

There is no universal schedule. Consider it after large deletions or when an external SSD has been used for a long time without a working automatic TRIM path. Excessive manual runs are unnecessary.

### Q: Should I run Real Test regularly?

No. It writes a large amount of data and is mainly a one-time compatibility test for a particular SSD/bridge/port combination.

### Q: Are the generated test files identical?

No. Their deterministic content is generated from a path-based seed, allowing each file's expected CRC to be recreated during verification.

### Q: What happens when one verification file fails?

The failure is logged, verification continues, and final totals show verified, passed, and failed counts. Any failed file makes the overall verification result fail.

### Q: Why did the selected disk change after Refresh?

The program preserves selection only when the same connection identity remains. If the disk was removed, replaced, or changed, it falls back safely and requires reselection.

### Q: What does **Exclude repetitive messages** hide?

Only repetitive informational lines inside the batch loop. Warnings, errors, plan summaries, and totals remain visible and logged.

### Q: Where is the application version shown?

It is read from the executable's embedded version resource and displayed in the window title.

---

## 13. Chatbot Knowledge Base

This section defines canonical facts and response guidance for support chatbots trained on this document.

### 13.1 Product identity

- Product name: **IODD TRIM Tool**
- Current documented version: **0.4.7.3**
- Supported OS: **64-bit Windows 10/11**
- Required privilege: **Administrator**
- Primary purpose: send TRIM requests to external SSDs through USB storage bridges
- Main tabs: **TRIM Execute**, **Drive Inspect**, **Real Test**
- Supported UI languages: Korean, English, Japanese, Simplified Chinese, Spanish, German, French, Russian

### 13.2 Canonical support facts

- Free-space mode supports mounted NTFS, exFAT, and FAT32 volumes.
- FAT12/FAT16 shown as `FAT` are not supported by free-space mode.
- Full TRIM requires a disk without volumes and is destructive.
- Windows ReTrim is the native NTFS fallback used by this application.
- `ATA-TRIM:NO` does not rule out SCSI UNMAP or DSM.
- Auto is the recommended UASP method.
- Dry-run does not prove hardware compatibility.
- A limited batch run is partial, not a complete-disk TRIM.
- Real Test writes heavily and is not a routine maintenance operation.
- Verification failures are logged individually and do not stop checking the remaining files.
- System-disk override and forced UASP method are not persisted.
- A successful command path cannot guarantee secure erasure or future hardware reliability.

### 13.3 Safety response policy

When a user asks about Full TRIM, deleting volumes, system disks, initialization, or Real Test:

1. Lead with the data-loss or write-endurance warning.
2. Recommend a verified backup.
3. Tell the user to verify model, serial, size, PD number, and drive letters.
4. Prefer Free-space mode when data must be retained.
5. Never imply that Dry-run or a successful TRIM is a secure-erasure certificate.
6. Never recommend forcing a raw method before Auto, a one-batch test, and basic cable/port checks.

### 13.4 Intent-to-answer examples

**User intent:** “I want to improve performance without deleting files.”  
**Answer:** Use Free-space TRIM only, verify the target disk, back up important files, test with Dry-run and one batch first, then run all batches if the bridge remains stable.

**User intent:** “I want to erase the whole SSD.”  
**Answer:** Full TRIM is destructive and requires all volumes to be removed. Back up first, verify the PhysicalDrive identity, and note that TRIM is not a certified secure erase.

**User intent:** “The program says ATA TRIM is unsupported.”  
**Answer:** That result concerns the ATA/SAT path reported by the bridge. If the device uses UAS, Auto may still succeed through DSM or SCSI UNMAP. Check the final summary.

**User intent:** “Can I use Windows ReTrim on exFAT?”  
**Answer:** Not through this application's Windows ReTrim fallback. Use Auto or a compatible SCSI UNMAP path; do not force an unsupported method casually.

**User intent:** “The log shows an error but says success at the end.”  
**Answer:** Auto mode may log rejection of an earlier path before a fallback succeeds. Use the final batch counts and completion message as the primary result.

**User intent:** “The USB disk disappeared during TRIM.”  
**Answer:** Treat the operation as failed. Physically reconnect the disk, wait for Windows, refresh, leave the method on Auto, and try a safer path or different cable/enclosure.

**User intent:** “Real Test found one bad file.”  
**Answer:** The complete verification result fails even if other files pass. Preserve the log, avoid important writes, check drive health, and test another bridge/cable before trusting the path.

**User intent:** “Can I run Real Test every week?”  
**Answer:** It is not recommended. Real Test fills most free space and consumes write endurance; use it primarily as a one-time compatibility test.

### 13.5 Information to request during troubleshooting

Ask the user for:

- Application version.
- Windows version.
- Whether the program was run as administrator.
- SSD model and capacity.
- USB enclosure/bridge model.
- BOT or UAS transport shown by the application.
- File system: NTFS, exFAT, FAT32, or other.
- Selected mode and expert method.
- Dry-run state, timeout, batch entries, and batch limit.
- Final summary and relevant warning/error lines.
- Whether the disk disconnected.
- Whether a hub was used.
- Whether the same result occurs with another cable, port, or enclosure.

Do not ask the user to publish an unmasked serial number. Encourage use of **Mask serial in log** before sharing logs.

### 13.6 Glossary

- **ATA Pass-Through:** encapsulates ATA commands through a SCSI/USB bridge.
- **BOT:** Bulk-Only Transport, the traditional USB mass-storage protocol.
- **CDB:** SCSI Command Descriptor Block.
- **DSM TRIM:** Windows device-management TRIM request issued through a mapped volume path.
- **Free-space bitmap:** file-system metadata identifying unused clusters.
- **LBA:** Logical Block Address.
- **Pinned Volume guard:** safety behavior that keeps certain mounted UAS/NTFS volumes online and favors Windows ReTrim over destabilizing raw paths.
- **ReTrim:** Windows request to notify storage again about currently free ranges.
- **SAT:** SCSI / ATA Translation performed by a bridge.
- **SCSI UNMAP:** SCSI command that marks logical blocks unused.
- **TRIM:** general term for notifying an SSD that logical blocks are no longer needed.
- **UAS/UASP:** USB Attached SCSI, a newer USB storage transport.
- **WRITE SAME:** SCSI command that may provide an unmap-capable fallback on some devices.

---

## 14. License and Disclaimer

IODD TRIM Tool is freeware.

- It may be used free of charge and copied or distributed.
- Commercial resale is prohibited.
- The software is provided **AS IS**, without warranty.
- The developer is not liable for data loss or other damage resulting from its use.
- Reverse engineering, decompilation, and source extraction are prohibited.

Copyright (c) 2025–2026 IODD. All rights reserved.

