How to Fix Slow SSD Speeds in Windows 11

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PC Technician
Windows 11PerformanceStorageOptimization

The Problem

You paid for an SSD but boot takes minutes, games stutter on load, and CrystalDiskMark scores are a fraction of the box specs. Windows 11 is usually fine—the drive may be nearly full, TRIM is off, the controller is stuck in IDE mode, or the SSD is failing and slowing down writes to protect itself.

C: drive full and everything crawls? Start with free up disk space. 100% disk in Task Manager? Different issue—fix 100% disk usage.

Symptoms

  • File copies to the SSD crawl compared to another PC with the same model.
  • Boot and app launch times got worse over months, not days.
  • CrystalDiskMark or manufacturer tools show far below rated sequential speeds.
  • SMART tools report reallocated sectors, wear, or "caution."

The Fix: Step-by-Step

Step 1: Confirm TRIM Is On

TRIM lets the SSD garbage-collect deleted blocks. Without it, performance tanks over time.

  1. Open Command Prompt or Terminal as Administrator.
  2. Run: fsutil behavior query DisableDeleteNotify
  3. Both NTFS and ReFS should show DisableDeleteNotify = 0 (TRIM enabled).
  4. If disabled: fsutil behavior set DisableDeleteNotify 0 → reboot.

Step 2: Verify AHCI / NVMe in BIOS (SATA and M.2)

Old IDE or RAID modes on SATA boards cap SSD throughput.

  1. Reboot → enter BIOS/UEFI (often Del, F2, or F10).
  2. Set storage to AHCI for SATA SSDs (not IDE). For NVMe, ensure the M.2 slot is enabled—no special mode needed on most boards.
  3. Warning: Switching AHCI on an old Windows install that was installed in IDE mode can blue-screen until you fix the registry first—search "enable AHCI without reinstall" for your build or reinstall if unsure.

Step 3: Leave 15–20% Free Space

SSDs slow dramatically when nearly full. Move media, uninstall games, or extend storage. Free space guide walks through safe cleanup.

Step 4: Update SSD Firmware and Storage Drivers

  1. Note the exact model (e.g. Samsung 990 Pro, WD Blue SN570).
  2. Download firmware tools from the SSD vendor—not a random "driver booster."
  3. Device Manager → Storage controllers → update Intel RST, AMD, or chipset storage drivers from your motherboard/laptop support page.

Step 5: Disable Hibernation and Oversized Page File (If C: Is Tiny)

powercfg /h off in admin CMD removes hiberfil.sys (often several GB). Only if you do not use hibernate. Tune page file in System → About → Advanced system settings → Performance → Advanced → Virtual memory if it is set absurdly large on a small drive.

Step 6: Check Health and Temperature

  1. Full walkthrough: check SSD and hard drive health with CrystalDiskInfo—watch Reallocated Sectors, Percent Used, Critical Warning.
  2. NVMe above ~70–80 °C under load throttles—improve case airflow or add a heatsink on the M.2 slot.
  3. If health is Caution or Bad, clone to a new drive immediately—do not keep writing to a dying disk.

Drive already failing or showing RAW? Stop using it for saves. Scan with Data Recovery Pro from another machine or boot USB before the controller gives up entirely.

Step 7: Benchmark Before and After

Use CrystalDiskMark with default settings—same test after each change. One bad USB enclosure or a SATA SSD in a USB adapter will look "broken"; test internal drives directly.

When It Is Not Software

  • Cheap DRAM-less SSDs slow under sustained writes—that is hardware, not TRIM.
  • SATA III port on an old laptop caps around ~550 MB/s even on a fast drive.
  • Failing cells: only replacement fixes it—software tweaks buy days, not years.