4 Practical Fixes to Speed Up a Slow SSD on Windows or macOS

The four practical fixes below will get a sluggish SSD moving again on Windows or macOS — without instantly buying a new drive — and explain the why, the how, and the caveats you need to avoid making things worse.

Background: why an SSD can feel slow even when it’s “fast”​

Solid-state drives (SSDs) replaced mechanical platters because they eliminate seek time and deliver massive improvements in boot speed, application launch times, and general responsiveness. The move from SATA SSDs to NVMe over PCIe amplified those gains by increasing sequential throughput and reducing latency dramatically — but NVMe doesn’t make drives immune to the realities of NAND flash, controllers, and system power-management choices. NVMe drives can saturate PCIe lanes and offer multi-gigabyte-per-second sequential speeds, but real-world performance still depends on free space, firmware, host drivers, thermal behaviour and power states. Practical, low-risk fixes exist for almost every common cause of slowdown.

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Overview: the four reliable ways to speed up a slow SSD​

• Keep free space available and manage storage proactively.
• Ensure TRIM and background optimization are working (manual TRIM only if needed).
• Update driver and SSD firmware, and verify vendor-recommended utilities.
• Adjust power and NVMe power-management settings so the drive isn’t being downclocked.

Each of those addresses a distinct root cause: lack of free blocks, delayed garbage collection, buggy firmware or drivers, and power-state throttling. The rest of this article explains how and why, with step-by-step actions for Windows and macOS and the trade-offs to consider.

1) Clear up space — the simplest, highest-impact fix​

Why free space matters​

SSDs require a buffer of unused blocks for the controller to perform wear leveling, garbage collection and to avoid frequent erase-write cycles. When the drive approaches full capacity the controller has far fewer empty blocks to use as scratch space; write amplification and internal data movement increase, and write speeds can fall sharply during sustained writes. Drive manufacturers and seagate support documents commonly recommend leaving a measurable percentage of capacity free to maintain peak performance. Typical guidance ranges from keeping 10–20% free, depending on NAND type and whether the drive uses an SLC cache.

What “full” actually means in practice​

• Light desktop use usually won’t be noticeably affected until around 80–85% full.
• Heavy sustained writes or budget drives with smaller SLC caches may show slowdowns at 75–85%.
• At 90%+ (and especially over 95%) sustained write performance can drop drastically and background cleanup can take a long time. These are practical estimates — exact thresholds vary by drive model, NAND generation and controller. Treat the numbers as rules of thumb, not guarantees.

Action steps (Windows)​

• Open Settings -> System -> Storage -> Storage Sense and turn on or tune Storage Sense to automatically remove temporary files and unused cloud-only copies. This helps reclaim space without manual deletion.
• Use an analyzer (Windows’ built-in Storage view or a third‑party disk-usage tool) to find large files and games; move them to an external HDD or another internal drive.
• Uninstall apps and games you no longer use; big installers, game directories and lossless media are common space hogs.

Action steps (macOS)​

• Apple Menu -> System Settings -> General -> Storage to review recommendations such as storing in iCloud, optimizing storage, or emptying the Trash.
• Delete or archive large media files; consider moving infrequently used libraries (video/photo/VMs) to an external drive.

Result and caveat​

Freeing space often gives an immediate performance bump for writes and improves background indexing and caching tasks. However, if you repeatedly fill and empty the drive as part of daily work, consider larger capacity or an additional drive rather than operating right at the threshold — sustained heavy write workloads are where bigger over-provisioning helps.

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2) Check and enforce TRIM / run the drive optimizer properly​

What TRIM and garbage collection do​

TRIM informs the SSD which logical blocks no longer contain valid data so the controller can reclaim them during idle time. Without TRIM, deleted data lingers until the controller performs garbage collection, which increases write amplification and slows subsequent writes. Modern desktop operating systems send TRIM automatically for internal SSDs, but behavior varies with external/portable drives and third‑party enclosures.

Windows: optimization schedule and manual runs​

Windows runs automatic optimization (including TRIM handling) by default on a weekly schedule. You can change the frequency (Daily/Weekly/Monthly) or run a manual optimize:

• Search the taskbar for “defrag” and open “Defragment and Optimize Drives”.
• Select your SSD and click “Optimize” to run a manual cycle; use “Change settings” to modify the schedule.
  Avoid running old HDD-style defrag utilities on SSDs — Windows recognizes SSDs and uses the correct optimize operations instead of a destructive defrag.

macOS: TRIM and third‑party drives​

macOS enables TRIM by default for Apple’s internal SSDs. For aftermarket SSDs, macOS historically limited TRIM to Apple-supplied drives but added the trimforce utility (since OS X 10.10.4) to enable TRIM for third‑party internal drives. Use Terminal:

• Check TRIM status: About This Mac -> System Report -> under Storage or SATA/Express you'll see “TRIM Support: Yes/No”.
• To enable TRIM for third-party drives: run sudo trimforce enable and follow the prompts; read the on-screen warnings and back up before proceeding. Apple warns this enables TRIM for all drives and certain older/quirky controllers may be incompatible.

When manual TRIM is unnecessary or harmful​

Most modern systems do TRIM automatically; forcing it repeatedly won’t improve life expectancy and can increase unnecessary writes. Only run manual optimization if you have a good reason (e.g., you recently deleted a lot of data and the drive isn’t recovering write performance) or your OS doesn’t issue TRIM for that drive.

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3) Update firmware and drivers — the maintenance many skip​

Why firmware matters​

SSD controllers and firmware coordinate wear leveling, SLC caching, thermal policies and the translation layer between file-system writes and NAND. Firmware updates can fix performance bugs, improve compatibility or address thermal throttling and stability issues. Major vendors publish their update utilities (Samsung Magician, Crucial Storage Executive, WD Dashboard, etc., and firmware updates are typically applied through vendor tools or bootable update ISOs. Always back up before applying firmware updates.

How to check your SSD model and firmware revision (Windows)​

• Device Manager -> Disk drives shows the model.
• PowerShell: Get-WmiObject -Class Win32_DiskDrive | Select-Object Model, FirmwareRevision shows firmware revision. Use that model to search the manufacturer’s support site for firmware updates or vendor tools.

Vendor tools and gotchas​

• Samsung Magician: Windows tool that reports firmware and offers an update flow (recommend backing up first). Magician is Windows-only; firmware ISO updates are available for platforms outside Windows.
• Crucial Storage Executive and other vendor utilities can update firmware, but user reports show occasional update failures or awkward workflows; manufacturers usually provide manual ISO files as a fallback. If the vendor utility fails, follow vendor documentation for manual ISO updates rather than downloading random firmware from third parties.

Cautions and best practice​

• Back up critical data before any firmware update.
• Apply updates only from the drive manufacturer’s official site or vendor tool.
• Avoid firmware updates from unofficial sources — corruption or mismatched firmware can brick a drive.
• If you rely on RAID, check vendor guidance: firmware updates often require single-drive update workflows or special procedures.

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4) Adjust power settings and NVMe power management (advanced, but often effective)​

The problem: NVMe power states and wake latency​

NVMe drives and the Windows NVMe driver support multiple power states. When the system prefers battery life, the NVMe driver may select a lower power state with higher latency or let the device enter deep sleep. On laptops and some desktops this can cause perceptible pauses when the drive is woken frequently for I/O bursts. Windows' StorNVMe driver maps system power schemes to NVMe idle timeouts and power-state selection, so changing power profiles can affect the drive’s responsiveness.

Windows quick adjustments​

• Settings -> System -> Power & battery: switch from “Best power efficiency” to “Balanced” or “Best performance” when plugged in. This changes the OS-wide bias toward responsiveness.
• Advanced Power Options -> PCI Express -> Link State Power Management: set to “Off” to avoid aggressive PCIe bus downclocking (this reduces latency at the cost of higher power draw). Tom’s Hardware documents this as a direct way to reduce latency for NVMe devices.

NVMe-specific advanced tweaks​

• Some systems expose advanced power options for NVMe idle timeout and APST parameters via the registry or OEM drivers. Reducing primary/secondary idle timeouts prevents the drive from entering deeper, higher-latency sleep states. These settings are advanced and differ by platform; change them only if you understand the implications (battery life vs latency) and can revert if necessary. The Microsoft NVMe design guide explains mapping between power schemes and NVMe power states.

Mac behaviour​

macOS’ “Low Power” modes primarily limit fan behaviour and CPU/GPU thermals rather than directly exposing NVMe power hints. Macs handle NVMe idle states internally; macOS doesn’t expose APST-like knobs to users. If you’re seeing stutter on a Mac, prioritize thermal management and firmware updates first.

Result and caveat​

Increasing performance by changing power settings will typically cost battery life on laptops and higher idle power draw on desktops. For desktop PCs where power is plentiful, set the system for performance; for laptops you’ll need to balance battery runtime vs responsiveness.

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Other useful tweaks and checks​

Don’t defragment an SSD​

Defragmentation is for spinning disks; it creates massive unnecessary writes on flash and reduces drive lifespan without meaningful benefit. Modern OSes will avoid full defrag on SSDs and run the appropriate optimize routines instead. If you see an old-style defrag tool being suggested, do not run it on an SSD.

Enable write caching and verify policies (Windows)​

Write caching can improve throughput by letting the host accumulate writes before committing to disk, but it increases the risk of data loss in a sudden power failure. If your system has a reliable UPS or you’re comfortable with the risk tradeoff, enabling write caching in Device Manager -> Disk drives -> Policies can yield gains; check vendor recommendations. Tom’s Hardware details when this helps.

Thermal throttling: keep NVMe cool​

NVMe controllers and NAND can throttle when temperatures climb (often around 70°C or higher). Ensure the module has adequate airflow or a heatsink in small or compact builds. If you’re doing heavy sustained writes (large file transfers, video exports), a hot drive will drop to lower speed states to protect the hardware. Vendor specs and many reviews call out thermal throttling as a common culprit for throughput collapse under sustained loads.

When to replace instead of optimize​

If the drive is old, has health warnings, or shows a large amount of reallocated/uncorrectable sectors in SMART, optimization will be a stopgap. Use a SMART tool to check health and replace the drive if failure is suspected. Firmware updates and cleanup can help performance, but they won’t resurrect exhausted NAND endurance.

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A step-by-step quick checklist (prioritized)​

• Free up 10–20% of capacity (move large files/games to external or secondary drive).
• Confirm TRIM is enabled: Windows will TRIM automatically; on Mac check System Report and use sudo trimforce enable only for third‑party internal SSDs after backing up.
• Run the OS drive optimizer / Defragment and Optimize Drives in Windows or reboot macOS after enabling TRIM to let the OS perform background maintenance.
• Update SSD firmware using the manufacturer’s official tool (Magician, Storage Executive, WD Dashboard) — back up first.
• For laptops, change Power & battery to Balanced/Best Performance while plugged in; for desktops disable aggressive PCIe Link State Power Management if you want absolute responsiveness. Monitor battery/heat trade-offs.
• If sustained large-file writes are the only issue, check NVMe thermal throttling and consider a larger drive with bigger SLC cache or better over-provisioning.

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Critical analysis: strengths, trade-offs and risks​

• Strengths: The four steps above are low-cost, often immediate improvements that address the most common and fixable performance bottlenecks: free space, absent TRIM, buggy firmware/drivers, and power-state-induced latency. They apply to both SATA and NVMe drives and to Windows and macOS users with small differences in tooling.
• Trade-offs: Increasing performance by changing power management settings consumes more battery and may increase thermal output. Enabling manufacturer tools (e.g., write caching) can marginally increase data-loss risk during a power failure. Updating firmware can resolve deep issues but carries a non-zero risk; always back up.
• Risks and uncertainty: Not every slowdown is caused by the SSD. Background CPU saturation, memory pressure, driver conflicts, or a failing controller on the motherboard can mimic storage slowness. If optimization steps don’t help, collect SMART data and run vendor diagnostic tools; consider reseating the drive or testing it in another machine. Vendor tools sometimes fail or misbehave; when they do, follow official manual update procedures from the manufacturer rather than third‑party instructions. Some specific thresholds (exact percent at which performance drops) are model-dependent — treat quoted percentages as estimated guidance, not hard rules.

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Final takeaway and checklist you can follow in the next 15–30 minutes​

• Free up 10–20% of the SSD’s capacity and confirm Storage Sense (Windows) or Storage recommendations (macOS) are active.
• Run Windows’ “Defragment and Optimize Drives” once manually or reboot macOS after enabling TRIM for non‑Apple SSDs if appropriate.
• Update drivers and firmware only from your SSD vendor’s official tool or support page and back up beforehand.
• For laptops, switch power mode to Balanced/Best Performance while plugged in; for desktops turn off aggressive PCIe Link State Power Management to minimize NVMe latency.

If, after these steps, performance is still poor, run SMART diagnostics, check for thermal throttling, and consider testing the drive in another machine or replacing it — a worn-out SSD will not be restored by software tweaks alone.
The steps above will resolve the majority of everyday SSD slowdowns while keeping your data safe and maintaining long-term drive health — the right mix of housekeeping, selective optimization, and cautious, vendor-approved updates.

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Source: Pocket-lint The 4 ways I speed up a sluggish SSD on a PC or Mac